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Bài 3: Góc nội tiếp

Bằng dụng cụ, hãy so sánh số đo của góc nội tiếp ∠(BAC) với số đo của cung bị chắn BC trong mỗi hình 16, 17, 18 dưới đây.

Toán Lớp 9
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.          By far the most important United States export product in the eighteenth and nineteenth centuries was cotton, favored by the European textile industry over flax or wool because it was easy to process and soft to tile touch. Mechanization of spinning and weaving allowed significant centralization and expansion in the textile industry duringthis period, and at the same time the demand for cotton increased dramatically. American producers were able to meet this demand largely because of tile invention of the cotton gin by Eli Whitney in 1793. Cotton could be grown throughout the South, but separating the fiber – or lint – from the seed was a laborious process. Sea island cotton was relatively easy to process by hand, because its fibers were long and seeds were concentrated at the base of the flower, but it demanded a long growing season, available only along the nation's eastern seacoast. Short-staple cotton required a much shorter growing season, but the shortness of the fibers and their mixture with seeds meant that a worker couldhand-process only about one pound per day. Whitney's gin was a hand-powered machine with revolving drums and metal teeth to pull cotton fibers away from seeds. Using the gin, a worker could produce up to 50 pounds of lint a day.   The later development of larger gins, powered by horses, water, or steam, multiplied productivity further.          The interaction of improved processing and high demand led to the rapid spread of the cultivation of cotton and to a surge in production. It became the main American export, dwarfing all others. In 1802, cotton composed 14 percent of total American exports by value. Cotton had a 36 percent share by 1810 and over a 50 percent sharein 1830. In 1860, 61 percent of the value of American exports was represented by cotton. In contrast, wheat and wheat flour composed only 6 percent of the value of American exports in that year. Clearly, cotton was king in the trade of the young republic. The growing market for cotton and other American agricultural products led to an unprecedented expansion of agricultural settlement, mostly in the eastern half of the United States---west of the Appalachian Mountains and east of the Mississippi River.The word "laborious" in line 6 is closest in meaning to

Tiếng Anh Tốt nghiệp THPT
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.          By far the most important United States export product in the eighteenth and nineteenth centuries was cotton, favored by the European textile industry over flax or wool because it was easy to process and soft to tile touch. Mechanization of spinning and weaving allowed significant centralization and expansion in the textile industry duringthis period, and at the same time the demand for cotton increased dramatically. American producers were able to meet this demand largely because of tile invention of the cotton gin by Eli Whitney in 1793. Cotton could be grown throughout the South, but separating the fiber – or lint – from the seed was a laborious process. Sea island cotton was relatively easy to process by hand, because its fibers were long and seeds were concentrated at the base of the flower, but it demanded a long growing season, available only along the nation's eastern seacoast. Short-staple cotton required a much shorter growing season, but the shortness of the fibers and their mixture with seeds meant that a worker couldhand-process only about one pound per day. Whitney's gin was a hand-powered machine with revolving drums and metal teeth to pull cotton fibers away from seeds. Using the gin, a worker could produce up to 50 pounds of lint a day.   The later development of larger gins, powered by horses, water, or steam, multiplied productivity further.          The interaction of improved processing and high demand led to the rapid spread of the cultivation of cotton and to a surge in production. It became the main American export, dwarfing all others. In 1802, cotton composed 14 percent of total American exports by value. Cotton had a 36 percent share by 1810 and over a 50 percent sharein 1830. In 1860, 61 percent of the value of American exports was represented by cotton. In contrast, wheat and wheat flour composed only 6 percent of the value of American exports in that year. Clearly, cotton was king in the trade of the young republic. The growing market for cotton and other American agricultural products led to an unprecedented expansion of agricultural settlement, mostly in the eastern half of the United States---west of the Appalachian Mountains and east of the Mississippi River.All of the following are mentioned in the passage as reasons for the increased demand for cotton EXCEPT 

Tiếng Anh Tốt nghiệp THPT
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Bài 3: Góc nội tiếp

Vì sao các góc ở hình 14 và hình 15 không phải là góc nội tiếp ?

Toán Lớp 9
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.          By far the most important United States export product in the eighteenth and nineteenth centuries was cotton, favored by the European textile industry over flax or wool because it was easy to process and soft to tile touch. Mechanization of spinning and weaving allowed significant centralization and expansion in the textile industry duringthis period, and at the same time the demand for cotton increased dramatically. American producers were able to meet this demand largely because of tile invention of the cotton gin by Eli Whitney in 1793. Cotton could be grown throughout the South, but separating the fiber – or lint – from the seed was a laborious process. Sea island cotton was relatively easy to process by hand, because its fibers were long and seeds were concentrated at the base of the flower, but it demanded a long growing season, available only along the nation's eastern seacoast. Short-staple cotton required a much shorter growing season, but the shortness of the fibers and their mixture with seeds meant that a worker couldhand-process only about one pound per day. Whitney's gin was a hand-powered machine with revolving drums and metal teeth to pull cotton fibers away from seeds. Using the gin, a worker could produce up to 50 pounds of lint a day.   The later development of larger gins, powered by horses, water, or steam, multiplied productivity further.          The interaction of improved processing and high demand led to the rapid spread of the cultivation of cotton and to a surge in production. It became the main American export, dwarfing all others. In 1802, cotton composed 14 percent of total American exports by value. Cotton had a 36 percent share by 1810 and over a 50 percent sharein 1830. In 1860, 61 percent of the value of American exports was represented by cotton. In contrast, wheat and wheat flour composed only 6 percent of the value of American exports in that year. Clearly, cotton was king in the trade of the young republic. The growing market for cotton and other American agricultural products led to an unprecedented expansion of agricultural settlement, mostly in the eastern half of the United States---west of the Appalachian Mountains and east of the Mississippi River.The word "favored" in line 2 is closest in meaning to

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 15)

Read the following passage and mark the letter A, B, C or D on you answer sheet to indicate the correct answer to each of the questionsWhen jazz began to lose its reputation as “low-down” music and to gain well-deserved acclaim among intellectuals, musicians began to feature many instruments previously considered inappropriate for jazz. Whereas before the 1950s, jazz musicians played only eight basic instruments in strict tempo, in this decade they started to improvise on the flute, electric organ, piccolo, accordion, cello, and even bagpipes, with the rhythm section composed for strings or piano. Big bands no longer dominated jazz, and most changes emerged from small combos, such as the Dave Brubeck Quartet and the Gerry Mulligan Quartet. The Gerry Mulligan Quartet proved that a small, modern band could sound complete without a piano; the rhythm section consisted only of a set of drums and a string bass.Jazz continued to move in new directions during the 1960s. Saxophonist and composer Ornette Coleman led a quartet playing “free” jazz that was atonal. Pianist Cecil Taylor also conducted similar experiments with music, and John Coltrane included melodies from India in his compositions. In the 1970s, musicians blended jazz and rock music into fusion jazz which combined the melodies and the improvisations of jazz with the rhythmic qualities of rock ‘n’ roll, with three or five beats to the bar and in other meter. The form of jazz music was greatly affected by electric instruments and electronic implements to intensify, distort, or amplify their sounds. However, the younger musicians of the time felt compelled to include a steady, swinging rhythm which they saw as a permanent and essential element in great jazz.The passage implies that representative jazz musicians_____

Tiếng Anh Tốt nghiệp THPT
Xem chi tiết 1.4 K lượt xem 5 năm trước
Tổng hợp đề thi thử THPTQG Hóa Học có lời giải chi tiết (Đề số 9)

Hỗn hợp X gồm 0,1 mol C2H4; 0,2 mol C2H2 và 0,7 mol H2. Nung nóng X trong bình kín có Ni xúc tác sau một thời gian thu dược 0,8 mol hỗn hợp Y. Biết Y phản ứng vừa đủ với 100ml dung dịch Br2 aM. Giá trị của a là

Hóa học Tốt nghiệp THPT
Xem chi tiết 286 lượt xem 5 năm trước
Tổng hợp đề thi thử THPT quốc gia môn tiếng anh có lời giải chi tiết (Đề số 7)

Mark  the  letter  A,  B,  C  or  D  in  your  answer  sheet  to  indicate  the  underlined  part  that  needs correction in each of the following questions.Richart (A) said the play (B) was very (C) entertaining and he recommended (D) to see it

Tiếng Anh Tốt nghiệp THPT
Xem chi tiết 1.1 K lượt xem 5 năm trước
Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.          By far the most important United States export product in the eighteenth and nineteenth centuries was cotton, favored by the European textile industry over flax or wool because it was easy to process and soft to tile touch. Mechanization of spinning and weaving allowed significant centralization and expansion in the textile industry duringthis period, and at the same time the demand for cotton increased dramatically. American producers were able to meet this demand largely because of tile invention of the cotton gin by Eli Whitney in 1793. Cotton could be grown throughout the South, but separating the fiber – or lint – from the seed was a laborious process. Sea island cotton was relatively easy to process by hand, because its fibers were long and seeds were concentrated at the base of the flower, but it demanded a long growing season, available only along the nation's eastern seacoast. Short-staple cotton required a much shorter growing season, but the shortness of the fibers and their mixture with seeds meant that a worker couldhand-process only about one pound per day. Whitney's gin was a hand-powered machine with revolving drums and metal teeth to pull cotton fibers away from seeds. Using the gin, a worker could produce up to 50 pounds of lint a day.   The later development of larger gins, powered by horses, water, or steam, multiplied productivity further.          The interaction of improved processing and high demand led to the rapid spread of the cultivation of cotton and to a surge in production. It became the main American export, dwarfing all others. In 1802, cotton composed 14 percent of total American exports by value. Cotton had a 36 percent share by 1810 and over a 50 percent sharein 1830. In 1860, 61 percent of the value of American exports was represented by cotton. In contrast, wheat and wheat flour composed only 6 percent of the value of American exports in that year. Clearly, cotton was king in the trade of the young republic. The growing market for cotton and other American agricultural products led to an unprecedented expansion of agricultural settlement, mostly in the eastern half of the United States---west of the Appalachian Mountains and east of the Mississippi River.The main point of the passage is that the eighteenth and nineteenth centuries were a time when       

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 15)

Read the following passage and mark the letter A, B, C or D on you answer sheet to indicate the correct answer to each of the questionsWhen jazz began to lose its reputation as “low-down” music and to gain well-deserved acclaim among intellectuals, musicians began to feature many instruments previously considered inappropriate for jazz. Whereas before the 1950s, jazz musicians played only eight basic instruments in strict tempo, in this decade they started to improvise on the flute, electric organ, piccolo, accordion, cello, and even bagpipes, with the rhythm section composed for strings or piano. Big bands no longer dominated jazz, and most changes emerged from small combos, such as the Dave Brubeck Quartet and the Gerry Mulligan Quartet. The Gerry Mulligan Quartet proved that a small, modern band could sound complete without a piano; the rhythm section consisted only of a set of drums and a string bass.Jazz continued to move in new directions during the 1960s. Saxophonist and composer Ornette Coleman led a quartet playing “free” jazz that was atonal. Pianist Cecil Taylor also conducted similar experiments with music, and John Coltrane included melodies from India in his compositions. In the 1970s, musicians blended jazz and rock music into fusion jazz which combined the melodies and the improvisations of jazz with the rhythmic qualities of rock ‘n’ roll, with three or five beats to the bar and in other meter. The form of jazz music was greatly affected by electric instruments and electronic implements to intensify, distort, or amplify their sounds. However, the younger musicians of the time felt compelled to include a steady, swinging rhythm which they saw as a permanent and essential element in great jazz.The author believes that the developments in jazz described in the passage ______

Tiếng Anh Tốt nghiệp THPT
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GIẢI NHANH BÀI TẬP HÓA VÔ CƠ DỰA VÀO ĐỒ THỊ

Dung dịch X chứa đồng thời các chất tan: NaOH 0,2M và Ba(OH)2 0,1M. Khi dẫn 0,336 lít khí CO2 hoặc 1,456 lít khí CO2 vào V ml dung dịch X đều thu được kết tủa có số gam bằng nhau (các thể tích khi đo ở điều kiện tiêu chuẩn). Thể tích V là

Hóa học Lớp 12
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food Resources may be affected by environmental changes, which will then cause problems. For a species requiring these resources. Other species may become better adapted to an Environment, resulting in competition and, ultimately, in the death of a species.The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time – a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life.           Perhaps the largest mass extinction was the one that occurred 225 million years ago, When approximately 95 percent of all species died, Mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass extinction.          One interesting, and controversial, finding is that extinctions during the past 250 Million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated tat extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.According to the passage, it is believed that the largest extinction of a species occurred

Tiếng Anh Tốt nghiệp THPT
Xem chi tiết 791 lượt xem 5 năm trước
Bài 2: Liên hệ giữa cung và dây

Chứng minh rằng đường kính đi qua điểm chính giữa của một cung thì vuông góc với dây cung ấy và ngược lại.

Toán Lớp 9
Xem chi tiết 36.4 K lượt xem 7 tháng trước
Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food Resources may be affected by environmental changes, which will then cause problems. For a species requiring these resources. Other species may become better adapted to an Environment, resulting in competition and, ultimately, in the death of a species.The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time – a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life.           Perhaps the largest mass extinction was the one that occurred 225 million years ago, When approximately 95 percent of all species died, Mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass extinction.          One interesting, and controversial, finding is that extinctions during the past 250 Million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated tat extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.In paragraph 3, the author makes which of the following statements about a species’ survival? 

Tiếng Anh Tốt nghiệp THPT
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Bài 2: Liên hệ giữa cung và dây

Chứng minh rằng đường kính đi qua điểm chính giữa của một cung thì đi qua trung điểm của dây cung căng cung ấy. Mệnh đề đảo có đúng không? Hãy nêu thêm điều kiện để mệnh đề đảo đúng.

Toán Lớp 9
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224 Bài tập ancol- phenol cực hay có đáp án (phần 4)

Tên gọi của anken (sản phẩm chính) thu được khi đun nóng ancol có công thức CH32CHCHOHCH3với dung dịch H2SO4 đặc là

Hóa học Lớp 11
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food Resources may be affected by environmental changes, which will then cause problems. For a species requiring these resources. Other species may become better adapted to an Environment, resulting in competition and, ultimately, in the death of a species.The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time – a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life.           Perhaps the largest mass extinction was the one that occurred 225 million years ago, When approximately 95 percent of all species died, Mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass extinction.          One interesting, and controversial, finding is that extinctions during the past 250 Million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated tat extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.The word “demise” in line 11 is closest in meaning to

Tiếng Anh Tốt nghiệp THPT
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GIẢI NHANH BÀI TẬP HÓA VÔ CƠ DỰA VÀO ĐỒ THỊ

Sục 4,48 lít CO2 (đktc) vào 2 lít dung dịch Ba(OH)2 2x mol/lít và NaOH x mol/lít. Sau khi các phản ứng xảy ra hoàn toàn thu được 19,7 gam kết tủa. Giá trị của x là:

Hóa học Lớp 12
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Bài 2: Liên hệ giữa cung và dây

Chứng minh rằng: trong một đường tròn, hai cung bị chắn giữa hai dây song song thì bằng nhau.

Toán Lớp 9
Xem chi tiết 59.5 K lượt xem 1 năm trước
Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food Resources may be affected by environmental changes, which will then cause problems. For a species requiring these resources. Other species may become better adapted to an Environment, resulting in competition and, ultimately, in the death of a species.The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time – a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life.           Perhaps the largest mass extinction was the one that occurred 225 million years ago, When approximately 95 percent of all species died, Mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass extinction.          One interesting, and controversial, finding is that extinctions during the past 250 Million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated tat extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.The word “finding” in line 18 is closest in meaning to

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG Hóa Học có lời giải chi tiết (Đề số 9)

Hòa tan  m gam hỗn hợp X gồm Fe và các oxit của sắt bằng dung dịch H2SO4 đặc, nóng dư đến phản ứng hoàn toàn thu được 80 gam muối khan và 2,24 lít SO2 (đktc). Vậy số mol H2SO4 đã tham gia phản ứng là?

Hóa học Tốt nghiệp THPT
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food Resources may be affected by environmental changes, which will then cause problems. For a species requiring these resources. Other species may become better adapted to an Environment, resulting in competition and, ultimately, in the death of a species.The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time – a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life.           Perhaps the largest mass extinction was the one that occurred 225 million years ago, When approximately 95 percent of all species died, Mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass extinction.          One interesting, and controversial, finding is that extinctions during the past 250 Million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated tat extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.According to paragraph 2, evidence from fossils suggests that

Tiếng Anh Tốt nghiệp THPT
Xem chi tiết 1.9 K lượt xem 5 năm trước
224 Bài tập ancol- phenol cực hay có đáp án (phần 4)

Có bao nhiêu ancol C5H12O khi tách nước chi tạo một anken duy nhất?

Hóa học Lớp 11
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Bài 2: Liên hệ giữa cung và dây

Cho tam giác ABC . Trên tia đối của tia AB lấy một điểm D sao cho AD = AC. Vẽ đường tròn tâm O ngoại tiếp tam giác DBC. Từ O lần lượt hạ các đường vuông góc OH, OK với BC và BD (H ∈ BC, K ∈ BD) So sánh hai cung nhỏ BD và BC

Toán Lớp 9
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224 Bài tập ancol- phenol cực hay có đáp án (phần 4)

Có bao nhiêu ancol no đơn chức mạch hở trong phân tử có từ 2 đến 5 nguyên tử cacbon mà khi tách nước (xt: H2SO4 đặc,to>170oC) chỉ thu được một anken duy nhất (không kể đồng phân hình học)?

Hóa học Lớp 11
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food Resources may be affected by environmental changes, which will then cause problems. For a species requiring these resources. Other species may become better adapted to an Environment, resulting in competition and, ultimately, in the death of a species.The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time – a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life.           Perhaps the largest mass extinction was the one that occurred 225 million years ago, When approximately 95 percent of all species died, Mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass extinction.          One interesting, and controversial, finding is that extinctions during the past 250 Million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated tat extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.Why is “ plankton” mentioned in line 15?

Tiếng Anh Tốt nghiệp THPT
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Bài 2: Liên hệ giữa cung và dây

Cho tam giác ABC . Trên tia đối của tia AB lấy một điểm D sao cho AD = AC. Vẽ đường tròn tâm O ngoại tiếp tam giác DBC. Từ O lần lượt hạ các đường vuông góc OH, OK với BC và BD (H ∈ BC, K ∈ BD)Chứng minh rằng OH > OK.

Toán Lớp 9
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Tổng hợp đề thi thử THPTQG Hóa Học có lời giải chi tiết (Đề số 9)

Chất nào sau đây không có khả năng tham gia phản ứng trùng hợp?

Hóa học Tốt nghiệp THPT
Xem chi tiết 286 lượt xem 5 năm trước
Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food Resources may be affected by environmental changes, which will then cause problems. For a species requiring these resources. Other species may become better adapted to an Environment, resulting in competition and, ultimately, in the death of a species.The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time – a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life.           Perhaps the largest mass extinction was the one that occurred 225 million years ago, When approximately 95 percent of all species died, Mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass extinction.          One interesting, and controversial, finding is that extinctions during the past 250 Million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated tat extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.Which of the following is NOT mentioned in paragraph 1 as resulting from rapid ecological change?

Tiếng Anh Tốt nghiệp THPT
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Bài 2: Liên hệ giữa cung và dây

Cho hai đường tròn bằng nhau (O) và (O') cắt nhau tại hai điểm A và B. Kẻ các đường kính AOC, AO'D. Gọi E là giao điểm thứ hai của AC với đường tròn (O').Chứng mình rằng B là điểm chính giữa của cung EBD (tức là điểm B chia cung EBD thành hai cung bằng nhau: BE⏜=BD⏜ )

Toán Lớp 9
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224 Bài tập ancol- phenol cực hay có đáp án (phần 4)

Khi tách nước các ancol bậc 2 có cùng công thức phân tử C5H12O thì số anken tối đa được tạo ra là:

Hóa học Lớp 11
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food Resources may be affected by environmental changes, which will then cause problems. For a species requiring these resources. Other species may become better adapted to an Environment, resulting in competition and, ultimately, in the death of a species.The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time – a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life.           Perhaps the largest mass extinction was the one that occurred 225 million years ago, When approximately 95 percent of all species died, Mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass extinction.          One interesting, and controversial, finding is that extinctions during the past 250 Million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated tat extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.What does the author say in paragraph 1 regarding most species in Earth’s history 

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG Hóa Học có lời giải chi tiết (Đề số 9)

Cho luồng khí CO dư đi qua ống sứ chứa m gam hỗn hợp Al2O3 và Fe3O4 đốt nóng. Sau phản ứng thấy còn lại là 14,14 gam chất rắn. Khí ra khỏi ống sứ được hấp thụ vào dung dịch Ca(OH)2 dư thu được 16 gam kết tủa. Giá trị của m là

Hóa học Tốt nghiệp THPT
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Bài 2: Liên hệ giữa cung và dây

Cho hai đường tròn bằng nhau (O) và (O') cắt nhau tại hai điểm A và B. Kẻ các đường kính AOC, AO'D. Gọi E là giao điểm thứ hai của AC với đường tròn (O').So sánh các cung nhỏ BC, BD.

Toán Lớp 9
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food Resources may be affected by environmental changes, which will then cause problems. For a species requiring these resources. Other species may become better adapted to an Environment, resulting in competition and, ultimately, in the death of a species.The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time – a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life.           Perhaps the largest mass extinction was the one that occurred 225 million years ago, When approximately 95 percent of all species died, Mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass extinction.          One interesting, and controversial, finding is that extinctions during the past 250 Million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated tat extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.The word “ultimately” in line 7 is closest in meaning to

Tiếng Anh Tốt nghiệp THPT
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224 Bài tập ancol- phenol cực hay có đáp án (phần 4)

Cho các ancol có tên sau: propan-1-ol(I); sec-butylic(II); etanol(III); 2-metylpropan-1-ol(IV); 2- metylpropan-2-ol(V); metylic (VI) và n-butylic (VII).Các ancol khi tách nước chỉ tạo một đồng phân anken duy nhất là:

Hóa học Lớp 11
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Bài 2: Liên hệ giữa cung và dây

Làm thế nào để chia được đường tròn thành sáu cung bằng nhau như trên hình 12?Hình 12

Toán Lớp 9
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer for each question below.It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species’ death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food Resources may be affected by environmental changes, which will then cause problems. For a species requiring these resources. Other species may become better adapted to an Environment, resulting in competition and, ultimately, in the death of a species.The fossil record reveals that extinction has occurred throughout the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time – a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life.           Perhaps the largest mass extinction was the one that occurred 225 million years ago, When approximately 95 percent of all species died, Mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass extinction.          One interesting, and controversial, finding is that extinctions during the past 250 Million years have tended to be more intense every 26 million years. This periodic extinction might be due to intersection of the Earth’s orbit with a cloud of comets, but this theory is purely speculative. Some researchers have also speculated tat extinction may often be random. That is, certain species may be eliminated and others may survive for no particular reason. A species’ survival may have nothing to do with its ability or inability to adapt. If so, some of evolutionary history may reflect a sequence of essentially random events.The word “it” in line 2 refers to

Tiếng Anh Tốt nghiệp THPT
Xem chi tiết 275 lượt xem 5 năm trước
Bài 2: Liên hệ giữa cung và dây

Vẽ đường tròn tâm O, bán kính R = 2cm. Nêu cách vẽ cung AB có số đo bằng 60o. Hỏi dây AB dài bao nhiêu xentimet?

Toán Lớp 9
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 15)

Read the following passage and mark the letter A, B, C or D on you answer sheet to indicate the correct answer to each of the questionsWhen jazz began to lose its reputation as “low-down” music and to gain well-deserved acclaim among intellectuals, musicians began to feature many instruments previously considered inappropriate for jazz. Whereas before the 1950s, jazz musicians played only eight basic instruments in strict tempo, in this decade they started to improvise on the flute, electric organ, piccolo, accordion, cello, and even bagpipes, with the rhythm section composed for strings or piano. Big bands no longer dominated jazz, and most changes emerged from small combos, such as the Dave Brubeck Quartet and the Gerry Mulligan Quartet. The Gerry Mulligan Quartet proved that a small, modern band could sound complete without a piano; the rhythm section consisted only of a set of drums and a string bass.Jazz continued to move in new directions during the 1960s. Saxophonist and composer Ornette Coleman led a quartet playing “free” jazz that was atonal. Pianist Cecil Taylor also conducted similar experiments with music, and John Coltrane included melodies from India in his compositions. In the 1970s, musicians blended jazz and rock music into fusion jazz which combined the melodies and the improvisations of jazz with the rhythmic qualities of rock ‘n’ roll, with three or five beats to the bar and in other meter. The form of jazz music was greatly affected by electric instruments and electronic implements to intensify, distort, or amplify their sounds. However, the younger musicians of the time felt compelled to include a steady, swinging rhythm which they saw as a permanent and essential element in great jazz.It can be inferred from the passage that small jazz bands ______

Tiếng Anh Tốt nghiệp THPT
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GIẢI NHANH BÀI TẬP HÓA VÔ CƠ DỰA VÀO ĐỒ THỊ

Sục 4,48 lít khí CO2 (đktc) vào 1 lít dung dịch hỗn hợp Ba(OH)2 0,12M và NaOH 0,06M. Sau khi các phản ứng xảy ra hoàn toàn thu được m gam kết tủa. Giá trị của m là

Hóa học Lớp 12
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224 Bài tập ancol- phenol cực hay có đáp án (phần 4)

Sản phẩm chính của sự đehiđrat hóa 3-metylpentan-2-ol là chất nào?

Hóa học Lớp 11
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer among A,B,C,D for each gap to complete it. Fill in the appropriate word in question 44      Most people feel that when they dream, they are (35)________ off to another world. On the (36)________, dreams are often  connected to our daily lives. When our whole (37)_________ is filled with something, when we are either very  upset (38)________ when we are in good spirit, a dream will represent this reality in symbols. It is often (39)_______ that we benefit from dreams because they help the spirit to heal itself when things (40)__________ wrong. Dreams are therefore a kind of escape, almost a holiday from (41)__________ life, with its fears and responsibilities. It is, however, a strange kind of holiday because whether we have a wonderful time or whether it turns (42)_________ to be a nightmare, we quickly forget it. Most dreams disappear forever, (43)_________ you are one of those people disciplined enough to write them down as soon as you (44)_________.

Tiếng Anh Tốt nghiệp THPT
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Bài 2: Liên hệ giữa cung và dây

Xem hình 11.Hãy viết giả thiết và kết luận của định lý(Không yêu cầu học sinh chứng minh định lý này)

Toán Lớp 9
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224 Bài tập ancol- phenol cực hay có đáp án (phần 4)

Chất Y là một ancol bậc II, có công thức phân tử là C6H14O. Đun Y với H2SO4 đặc ở 170°C chỉ tạo ra một anken duy nhất. Vậy tên gọi nào sau đây của Y là thỏa mãn:

Hóa học Lớp 11
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Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer among A,B,C,D for each gap to complete it. Fill in the appropriate word in question 43      Most people feel that when they dream, they are (35)________ off to another world. On the (36)________, dreams are often  connected to our daily lives. When our whole (37)_________ is filled with something, when we are either very  upset (38)________ when we are in good spirit, a dream will represent this reality in symbols. It is often (39)_______ that we benefit from dreams because they help the spirit to heal itself when things (40)__________ wrong. Dreams are therefore a kind of escape, almost a holiday from (41)__________ life, with its fears and responsibilities. It is, however, a strange kind of holiday because whether we have a wonderful time or whether it turns (42)_________ to be a nightmare, we quickly forget it. Most dreams disappear forever, (43)_________ you are one of those people disciplined enough to write them down as soon as you (44)_________.

Tiếng Anh Tốt nghiệp THPT
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Bài 2: Liên hệ giữa cung và dây

Hãy chứng minh định lý trên.

Toán Lớp 9
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224 Bài tập ancol- phenol cực hay có đáp án (phần 4)

Ete hóa 2 ancol đơn chức cùng dãy đồng đẳng thu được 3 ete. Trong đó 1 ete có khối lượng mol phân tử bằng khối lượng mol phân tử của 1 trong 2 ancol. Vậy 2 ancol này không thể là

Hóa học Lớp 11
Xem chi tiết 625 lượt xem 5 năm trước
Kỳ thi thử thpt quốc gia lần 1 năm 2019 môn Tiếng Anh cực hay có lời giải(Đề 15)

Read the passage and choose the best answer among A,B,C,D for each gap to complete it. Fill in the appropriate word in question 42      Most people feel that when they dream, they are (35)________ off to another world. On the (36)________, dreams are often  connected to our daily lives. When our whole (37)_________ is filled with something, when we are either very  upset (38)________ when we are in good spirit, a dream will represent this reality in symbols. It is often (39)_______ that we benefit from dreams because they help the spirit to heal itself when things (40)__________ wrong. Dreams are therefore a kind of escape, almost a holiday from (41)__________ life, with its fears and responsibilities. It is, however, a strange kind of holiday because whether we have a wonderful time or whether it turns (42)_________ to be a nightmare, we quickly forget it. Most dreams disappear forever, (43)_________ you are one of those people disciplined enough to write them down as soon as you (44)_________.

Tiếng Anh Tốt nghiệp THPT
Xem chi tiết 1 K lượt xem 5 năm trước
Luyện tập trang 69-70

Trên đường tròn tâm O lấy ba điểm A, B, C sao cho AOB^=100o sđ AC⏜=45o . Tính số đo của cung nhỏ BC và cung lớn BC. (Xét cả hai trường hợp: điểm C nằm trên cung nhỏ AB, điểm C nằm trên cung lớn AB).

Toán Lớp 9
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