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25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Trong mặt phẳng Oxy, ảnh của điểm M(3;3) qua phép quay Q(O; 45o) là:

Toán Lớp 11
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the underlined part that needs correction in each of the following questions.We must stop discrimination on people coming from the rural area.

Tiếng Anh Lớp 10
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25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Trong mặt phẳng Oxy , qua phép quay Q(O; 90o), M’(3; -2) là ảnh của điểm nào sau đây?

Toán Lớp 11
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25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Trong mặt phẳng Oxy, ảnh của điểm M (-6; 1) qua phép quay QO; 90o là

Toán Lớp 11
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the underlined part that needs correction in each of the following questions.A lot of people think that marriage women shouldn't pursue a career.

Tiếng Anh Lớp 10
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25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Khẳng định nào sau đây là sai:

Toán Lớp 11
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25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Khẳng định nào sau đây là sai?

Toán Lớp 11
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.Women do not yet have equal rights in the family in this area.

Tiếng Anh Lớp 10
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions. We never allow any kind of discrimination against girls at school.

Tiếng Anh Lớp 10
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25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Cho v→(-4;2) và đường thẳng ∆':2x - y - 5 = 0. Hỏi ∆' là ảnh của đường thẳng ∆ nào qua Tv→

Toán Lớp 11
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.Our government has done a lot to eliminate gender inequality.

Tiếng Anh Lớp 10
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.In some rural areas, women and girls are forced to do most of the housework.

Tiếng Anh Lớp 10
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions. This year, more girls enrolled on courses in art and design.

Tiếng Anh Lớp 10
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25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Cho v→(3;3) và đường tròn (C): x2 + y2 - 2x + 4y - 4 = 0. ảnh của (C) qua Tv→ là (C’).

Toán Lớp 11
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

Tiếng Anh Lớp 10
Xem chi tiết 1.4 K lượt xem 5 năm trước
Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

Tiếng Anh Lớp 10
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

Tiếng Anh Lớp 10
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25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Cho v→(-1;5) và điểm M’(4;2). Biết M’ là ảnh của M qua phép tịnh tiến Tv→ . Tìm M.

Toán Lớp 11
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Tổng hợp 20 đề thi thử THPT quốc gia môn Toán cực hay có lời giải chi tiết (Đề số 8)

Cho hình hộp chữ nhật  ABCD.A'B'C'D' có AB=2a, AD=3a, AA'=3a. Gọi E là trung điểm B'C'. Thể tích khối chóp E.BCD bằng

Toán Tốt nghiệp THPT
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

Tiếng Anh Lớp 10
Xem chi tiết 6.6 K lượt xem 5 năm trước
25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Cho đường tròn (C) có tâm O và đường kính AB. Gọi ∆ là tiếp tuyến của (C) tại điểm A. Phép tịnh tiến TAB⇀ biến ∆ thành:

Toán Lớp 11
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Đề kiểm tra 15 phút Tiếng Anh 10 Thí điểm Học kì 2 có đáp án (Đề 1)

Mark the letter A, B, C, or D to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

Tiếng Anh Lớp 10
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25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Cho hình bình hành ABCD. Phép tịnh tiến TAB→ + AD→ biến điểm A thành điểm:

Toán Lớp 11
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25 câu Trắc nghiệm Ôn tập Chương 1 Hình học 11 có đáp án

Cho hình bình hành ABCD. Phép tịnh tiến TDA→ biến:

Toán Lớp 11
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Tổng hợp 20 đề thi thử THPT quốc gia môn Toán cực hay có lời giải chi tiết (Đề số 8)

Gọi A là điểm biểu diễn số phức z=3+4i và B là điểm biểu diễn số phức z=-3+i Khẳng định nào sau đây là đúng?

Toán Tốt nghiệp THPT
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Tổng hợp 20 đề thi thử THPT quốc gia môn Toán cực hay có lời giải chi tiết (Đề số 8)

Tổng bình phương module các nghiệm của phương trình x2 + (i-1) x+2+i=0  trong tập số phức là:

Toán Tốt nghiệp THPT
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Tổng hợp 20 đề thi thử THPT quốc gia môn Toán cực hay có lời giải chi tiết (Đề số 8)

Tích phân I= ∫2 3 1 x2 -1 bằng với tích phân nào sau đây?

Toán Tốt nghiệp THPT
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22 câu Trắc nghiệm Phép vị tự có đáp án

Trong mặt phẳng tọa độ Oxy phép vị tự tâm H(1;-3) tỉ số k = 1/2, biến đường tròn (C) có phương trình : x - 22 + y - 32 = 32 thành đường tròn (C’) có phương trình:

Toán Lớp 11
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Tổng hợp 20 đề thi thử THPT quốc gia môn Toán cực hay có lời giải chi tiết (Đề số 8)

Cho hàm số y=ex +e-x .Nghiệm của phương trình y'=0 là:

Toán Tốt nghiệp THPT
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22 câu Trắc nghiệm Phép vị tự có đáp án

Trong mặt phẳng tọa độ Oxy phép vị tự tâm H(1;0) tỉ số k = 2, biến đường tròn (C) có phương trình : x2 + 4x + y2 + 6y = 12 thành đường tròn (C’) có phương trình

Toán Lớp 11
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Read the following passage and mark the letter A,B,C or D on your answer sheet to indicate the correct answer to each of the questionsReading to oneself is a modern activity which was almost unknown to the scholars of the classical and medieval worlds, while during the fifteenth century the term “reading” undoubtedly meant reading aloud. Only during the nineteenth century did silent reading become commonplace.One should be wary, however, of assuming that silent reading came about simply because reading aloud was a distraction to others. Examinations of factors related to the historical development of silent reading have revealed that it became the usual mode of reading for most adults mainly because the tasks themselves changed in character.The last century saw a steady gradual increase in literacy and thus in the number of readers. As the number of readers increased, the number of potential listeners declined and thus there was some reduction in the need to read aloud. As reading for the benefit of listeners grew less common, so came the flourishing of reading as a private activity in such public places as libraries, railway carriages and offices, where reading aloud would cause distraction to other readers.Towards the end of the century, there was still considerable argument over whether books should be used for information or treated respectfully and over whether the reading of materials such as newspapers was in some way mentally weakening. Indeed, this argument remains with us still in education. However, whateverits virtues, the old shared literacy culture had gone and was replaced by the printed mass media on the one hand and by books and periodicals for a specialised readership on the other.By the end of the twentieth century, students were being recommended to adopt attitudes to books and to use reading skills which were inappropriate, if not impossible, for the oral reader. The social, cultural and technological changes in the century had greatly altered what the term “reading” implied.Silent reading, especially in public places, flourished mainly because of ___.

Tiếng Anh Lớp 10
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Tổng hợp 20 đề thi thử THPT quốc gia môn Toán cực hay có lời giải chi tiết (Đề số 8)

Đạo hàm của hàm số y=x+2 x-1  ln(x+2)  là

Toán Tốt nghiệp THPT
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Read the following passage and mark the letter A,B,C or D on your answer sheet to indicate the correct answer to each of the questionsReading to oneself is a modern activity which was almost unknown to the scholars of the classical and medieval worlds, while during the fifteenth century the term “reading” undoubtedly meant reading aloud. Only during the nineteenth century did silent reading become commonplace.One should be wary, however, of assuming that silent reading came about simply because reading aloud was a distraction to others. Examinations of factors related to the historical development of silent reading have revealed that it became the usual mode of reading for most adults mainly because the tasks themselves changed in character.The last century saw a steady gradual increase in literacy and thus in the number of readers. As the number of readers increased, the number of potential listeners declined and thus there was some reduction in the need to read aloud. As reading for the benefit of listeners grew less common, so came the flourishing of reading as a private activity in such public places as libraries, railway carriages and offices, where reading aloud would cause distraction to other readers.Towards the end of the century, there was still considerable argument over whether books should be used for information or treated respectfully and over whether the reading of materials such as newspapers was in some way mentally weakening. Indeed, this argument remains with us still in education. However, whateverits virtues, the old shared literacy culture had gone and was replaced by the printed mass media on the one hand and by books and periodicals for a specialised readership on the other.By the end of the twentieth century, students were being recommended to adopt attitudes to books and to use reading skills which were inappropriate, if not impossible, for the oral reader. The social, cultural and technological changes in the century had greatly altered what the term “reading” implied.The development of silent reading during the last century indicated ______.

Tiếng Anh Lớp 10
Xem chi tiết 336 lượt xem 5 năm trước
Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Read the following passage and mark the letter A,B,C or D on your answer sheet to indicate the correct answer to each of the questionsReading to oneself is a modern activity which was almost unknown to the scholars of the classical and medieval worlds, while during the fifteenth century the term “reading” undoubtedly meant reading aloud. Only during the nineteenth century did silent reading become commonplace.One should be wary, however, of assuming that silent reading came about simply because reading aloud was a distraction to others. Examinations of factors related to the historical development of silent reading have revealed that it became the usual mode of reading for most adults mainly because the tasks themselves changed in character.The last century saw a steady gradual increase in literacy and thus in the number of readers. As the number of readers increased, the number of potential listeners declined and thus there was some reduction in the need to read aloud. As reading for the benefit of listeners grew less common, so came the flourishing of reading as a private activity in such public places as libraries, railway carriages and offices, where reading aloud would cause distraction to other readers.Towards the end of the century, there was still considerable argument over whether books should be used for information or treated respectfully and over whether the reading of materials such as newspapers was in some way mentally weakening. Indeed, this argument remains with us still in education. However, whateverits virtues, the old shared literacy culture had gone and was replaced by the printed mass media on the one hand and by books and periodicals for a specialised readership on the other.By the end of the twentieth century, students were being recommended to adopt attitudes to books and to use reading skills which were inappropriate, if not impossible, for the oral reader. The social, cultural and technological changes in the century had greatly altered what the term “reading” implied.The word “commonplace” in the first paragraph mostly means “______”.

Tiếng Anh Lớp 10
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22 câu Trắc nghiệm Phép vị tự có đáp án

Trong mặt phẳng tọa độ Oxy phép vị tự tâm O(0;0) tỉ số k = 2 biến đường tròn (C) có phương trình: x2 + y2 + 4x + 6y = 12 thành đường tròn (C’) có phương trình

Toán Lớp 11
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Read the following passage and mark the letter A,B,C or D on your answer sheet to indicate the correct answer to each of the questionsReading to oneself is a modern activity which was almost unknown to the scholars of the classical and medieval worlds, while during the fifteenth century the term “reading” undoubtedly meant reading aloud. Only during the nineteenth century did silent reading become commonplace.One should be wary, however, of assuming that silent reading came about simply because reading aloud was a distraction to others. Examinations of factors related to the historical development of silent reading have revealed that it became the usual mode of reading for most adults mainly because the tasks themselves changed in character.The last century saw a steady gradual increase in literacy and thus in the number of readers. As the number of readers increased, the number of potential listeners declined and thus there was some reduction in the need to read aloud. As reading for the benefit of listeners grew less common, so came the flourishing of reading as a private activity in such public places as libraries, railway carriages and offices, where reading aloud would cause distraction to other readers.Towards the end of the century, there was still considerable argument over whether books should be used for information or treated respectfully and over whether the reading of materials such as newspapers was in some way mentally weakening. Indeed, this argument remains with us still in education. However, whateverits virtues, the old shared literacy culture had gone and was replaced by the printed mass media on the one hand and by books and periodicals for a specialised readership on the other.By the end of the twentieth century, students were being recommended to adopt attitudes to books and to use reading skills which were inappropriate, if not impossible, for the oral reader. The social, cultural and technological changes in the century had greatly altered what the term “reading” implied.Reading aloud was more common in the medieval world because ______.

Tiếng Anh Lớp 10
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

The team reached the top of the mountain. The team spent a night there.

Tiếng Anh Lớp 10
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Mark the letter A, B, C, or D on your answer sheet to indicate the semtence that best combines each pair of sentences in the following questionsPeople should not throw rubbish in the park. People should not cut down the trees in the park.

Tiếng Anh Lớp 10
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Read the following passage and mark the letter A, B, C, or D on your answer answer to each of the questionsAn air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely . Air pollution requires a very flexible definition that permits continuous change. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled – a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions. Many of more important air pollutants such as sulfur oxides, carbon monoxide, and nitrogen oxides, are found in nature. As the Earth developed, the concentrations of these pollutants were altered by various chemical reactions; they became components in biogeochemical cycle. Theseserve as an air purification scheme by allowing the compounds to move from the air to the water or soil on a global basis, nature's output of these compounds dwarfs that resulting from human activities.However, human production usually occurs in a localized area, such as a city. In this localized regions, human output may be dominant and may temporarily overload the natural purification scheme of the cycle. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0.08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however, as a natural level of 0.1 ppm and is not usually a pollutant until its level reaches about 15 ppm.Which of the following is best supported by the passage?

Tiếng Anh Lớp 10
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22 câu Trắc nghiệm Phép vị tự có đáp án

Trong mặt phẳng tọa độ Oxy phép vị tự tâm O(0;0) tỉ số k = -2, biến đường tròn (C) có phương trình: x2 + y2 = 9 thành đường tròn (C’) có phương trình:

Toán Lớp 11
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Read the following passage and mark the letter A, B, C, or D on your answer answer to each of the questionsAn air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely . Air pollution requires a very flexible definition that permits continuous change. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled – a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions. Many of more important air pollutants such as sulfur oxides, carbon monoxide, and nitrogen oxides, are found in nature. As the Earth developed, the concentrations of these pollutants were altered by various chemical reactions; they became components in biogeochemical cycle. Theseserve as an air purification scheme by allowing the compounds to move from the air to the water or soil on a global basis, nature's output of these compounds dwarfs that resulting from human activities.However, human production usually occurs in a localized area, such as a city. In this localized regions, human output may be dominant and may temporarily overload the natural purification scheme of the cycle. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0.08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however, as a natural level of 0.1 ppm and is not usually a pollutant until its level reaches about 15 ppm.The word "detectable" in the third paragraph is closest in meaning to

Tiếng Anh Lớp 10
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Tổng hợp đề thi vào lớp 6 môn Toán cực hay có lời giải chi tiết (Đề 32)

Tính tổng S =12.5+15.8+18.11+111.14+...+197.100

Toán Lớp 5
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Read the following passage and mark the letter A, B, C, or D on your answer answer to each of the questionsAn air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely . Air pollution requires a very flexible definition that permits continuous change. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled – a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions. Many of more important air pollutants such as sulfur oxides, carbon monoxide, and nitrogen oxides, are found in nature. As the Earth developed, the concentrations of these pollutants were altered by various chemical reactions; they became components in biogeochemical cycle. Theseserve as an air purification scheme by allowing the compounds to move from the air to the water or soil on a global basis, nature's output of these compounds dwarfs that resulting from human activities.However, human production usually occurs in a localized area, such as a city. In this localized regions, human output may be dominant and may temporarily overload the natural purification scheme of the cycle. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0.08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however, as a natural level of 0.1 ppm and is not usually a pollutant until its level reaches about 15 ppm.The word "localized” is closest in meaning to

Tiếng Anh Lớp 10
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Tổng hợp 20 đề thi thử THPT quốc gia môn Toán cực hay có lời giải chi tiết (Đề số 8)

Bất phương trình log12   (x-1)> log1 4  x2 có tập nghiệm là

Toán Tốt nghiệp THPT
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Read the following passage and mark the letter A, B, C, or D on your answer answer to each of the questionsAn air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely . Air pollution requires a very flexible definition that permits continuous change. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled – a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions. Many of more important air pollutants such as sulfur oxides, carbon monoxide, and nitrogen oxides, are found in nature. As the Earth developed, the concentrations of these pollutants were altered by various chemical reactions; they became components in biogeochemical cycle. Theseserve as an air purification scheme by allowing the compounds to move from the air to the water or soil on a global basis, nature's output of these compounds dwarfs that resulting from human activities.However, human production usually occurs in a localized area, such as a city. In this localized regions, human output may be dominant and may temporarily overload the natural purification scheme of the cycle. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0.08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however, as a natural level of 0.1 ppm and is not usually a pollutant until its level reaches about 15 ppm.For which of the following reasons can natural pollutants play an important role in controlling air pollution?

Tiếng Anh Lớp 10
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Tổng hợp đề thi vào lớp 6 môn Toán cực hay có lời giải chi tiết (Đề 32)

Cho tam giác vuông có hai cạnh góc vuông là 12cm và 8cm. Tính diện tích tam giác vuông đó.

Toán Lớp 5
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Read the following passage and mark the letter A, B, C, or D on your answer answer to each of the questionsAn air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely . Air pollution requires a very flexible definition that permits continuous change. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled – a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions. Many of more important air pollutants such as sulfur oxides, carbon monoxide, and nitrogen oxides, are found in nature. As the Earth developed, the concentrations of these pollutants were altered by various chemical reactions; they became components in biogeochemical cycle. Theseserve as an air purification scheme by allowing the compounds to move from the air to the water or soil on a global basis, nature's output of these compounds dwarfs that resulting from human activities.However, human production usually occurs in a localized area, such as a city. In this localized regions, human output may be dominant and may temporarily overload the natural purification scheme of the cycle. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0.08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however, as a natural level of 0.1 ppm and is not usually a pollutant until its level reaches about 15 ppm.The word "these" in the second paragraph is closest in meaning to

Tiếng Anh Lớp 10
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Tổng hợp đề thi vào lớp 6 môn Toán cực hay có lời giải chi tiết (Đề 32)

Một ô tô và một xe máy khởi hành cùng một lúc và đi ngược chiều nhau. Ô tô đi từ A với vận tốc 48,5 km/giờ, xe máy đi từ B với vận tốc 33,5 km/giờ. Sau 1 giờ 30 phút ô tô và xe máy gặp nhau tại C. Hỏi quãng đường AB dài bao nhiêu ki- lô – mét?

Toán Lớp 5
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Đề thi Tiếng Anh 10 Thí điểm Học kì 1 có đáp án (Đề 5)

Read the following passage and mark the letter A, B, C, or D on your answer answer to each of the questionsAn air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely . Air pollution requires a very flexible definition that permits continuous change. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled – a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions. Many of more important air pollutants such as sulfur oxides, carbon monoxide, and nitrogen oxides, are found in nature. As the Earth developed, the concentrations of these pollutants were altered by various chemical reactions; they became components in biogeochemical cycle. Theseserve as an air purification scheme by allowing the compounds to move from the air to the water or soil on a global basis, nature's output of these compounds dwarfs that resulting from human activities.However, human production usually occurs in a localized area, such as a city. In this localized regions, human output may be dominant and may temporarily overload the natural purification scheme of the cycle. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0.08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however, as a natural level of 0.1 ppm and is not usually a pollutant until its level reaches about 15 ppm.It can be inferred from the first paragraph that

Tiếng Anh Lớp 10
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Tổng hợp đề thi vào lớp 6 môn Toán cực hay có lời giải chi tiết (Đề 32)

Tìm x: b) x+13=726.136

Toán Lớp 5
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