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Bài 23: Từ thông. Cảm ứng điện từ

Một khung dây hình chữ nhật có chiều dài 25cm, được đặt vuông góc với các đường sức từ của một từ trường đều có B=4.10-3T. Từ thông xuyên qua khung dây là 10-4Wb, chiều rộng của khung dây nói trên là

Vật lý Lớp 11
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BỘ ĐỀ THI THPT QUỐC GIA CHUẨN CẤU TRÚC BỘ GIÁO DỤC MÔN TIẾNG ANH (P9)

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 questions from 28 to 34.Scientists do not yet thoroughly understand just how the body of an individual becomes sensitive to a substance that is harmless or even wholesome for the average person. Milk, wheat, and egg, for example, rank among the most healthful and widely used foods. Yet these foods can cause persons sensitive to them to suffer greatly. At first, the body of the individual is not harmed by coming into contact with the substance. After a varying interval of time, usually longer than a few weeks, the body becomes sensitive to it, and an allergy has begun to develop. Sometimes it’s hard to figure out if you have a food allergy, since it can show up so many different ways. Your symptoms could be caused by many other problems. You may have rashes, hives, joint pains mimicking arthritis, headaches, irritability, or depression. The most common food allergies are to milk, eggs, seafood, wheat, nuts, seeds, chocolate, oranges, and tomatoes. Many of these allergies will not develop if these foods are not fed to an infant until her or his intestines mature at around seven months. Breast milk also tends to be protective. Migraines can be set off by foods containing tyramine, phenathylamine, monosodium glutamate, or sodium nitrate. Common foods which contain these are chocolate, aged cheeses, sour cream, red wine, pickled herring, chicken livers, avocados, ripe bananas, cured meats, many Oriental and prepared foods (read the labels!). Some people have been successful in treating their migraines with supplements of B-vitamins, particularly B6 and niacin. Children who are hyperactive may benefit from eliminating food additives, especially colorings, and foods high in salicylates trom their diets.The word “symptoms” is closest in meaning to ____________.

Tiếng Anh Tốt nghiệp THPT
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Đề minh họa đề thi Vật Lí cực hay có lời giải (Đề số 3)

Chuông gió như hình bên, thường được làm từ những thanh hình ống có chiều dài khác nhau để 

Vật lý Tốt nghiệp THPT
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BỘ ĐỀ THI THPT QUỐC GIA CHUẨN CẤU TRÚC BỘ GIÁO DỤC MÔN TIẾNG ANH (P9)

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 questions from 28 to 34.Scientists do not yet thoroughly understand just how the body of an individual becomes sensitive to a substance that is harmless or even wholesome for the average person. Milk, wheat, and egg, for example, rank among the most healthful and widely used foods. Yet these foods can cause persons sensitive to them to suffer greatly. At first, the body of the individual is not harmed by coming into contact with the substance. After a varying interval of time, usually longer than a few weeks, the body becomes sensitive to it, and an allergy has begun to develop. Sometimes it’s hard to figure out if you have a food allergy, since it can show up so many different ways. Your symptoms could be caused by many other problems. You may have rashes, hives, joint pains mimicking arthritis, headaches, irritability, or depression. The most common food allergies are to milk, eggs, seafood, wheat, nuts, seeds, chocolate, oranges, and tomatoes. Many of these allergies will not develop if these foods are not fed to an infant until her or his intestines mature at around seven months. Breast milk also tends to be protective. Migraines can be set off by foods containing tyramine, phenathylamine, monosodium glutamate, or sodium nitrate. Common foods which contain these are chocolate, aged cheeses, sour cream, red wine, pickled herring, chicken livers, avocados, ripe bananas, cured meats, many Oriental and prepared foods (read the labels!). Some people have been successful in treating their migraines with supplements of B-vitamins, particularly B6 and niacin. Children who are hyperactive may benefit from eliminating food additives, especially colorings, and foods high in salicylates trom their diets.According to the passage, the difficulty in diagnosing allergies to foods is due to ____________

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 4)

Đặt vào hai đầu đoạn mạch R, L, C mắc nối tiếp một điện áp xoay chiều có biểu thức u=200cos(100πt)V.Biết cuộn dây thuần cảm có độ tự cảm L, điện trở R = 100 Ω, tụ điện có điện dung C = 31,8 μF. Mạch điện tiêu thụ công suất là 100 W, khi đó độ tự cảm L có giá trị là

Vật lý Tốt nghiệp THPT
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BỘ ĐỀ THI THPT QUỐC GIA CHUẨN CẤU TRÚC BỘ GIÁO DỤC MÔN TIẾNG ANH (P9)

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 questions from 28 to 34.Scientists do not yet thoroughly understand just how the body of an individual becomes sensitive to a substance that is harmless or even wholesome for the average person. Milk, wheat, and egg, for example, rank among the most healthful and widely used foods. Yet these foods can cause persons sensitive to them to suffer greatly. At first, the body of the individual is not harmed by coming into contact with the substance. After a varying interval of time, usually longer than a few weeks, the body becomes sensitive to it, and an allergy has begun to develop. Sometimes it’s hard to figure out if you have a food allergy, since it can show up so many different ways. Your symptoms could be caused by many other problems. You may have rashes, hives, joint pains mimicking arthritis, headaches, irritability, or depression. The most common food allergies are to milk, eggs, seafood, wheat, nuts, seeds, chocolate, oranges, and tomatoes. Many of these allergies will not develop if these foods are not fed to an infant until her or his intestines mature at around seven months. Breast milk also tends to be protective. Migraines can be set off by foods containing tyramine, phenathylamine, monosodium glutamate, or sodium nitrate. Common foods which contain these are chocolate, aged cheeses, sour cream, red wine, pickled herring, chicken livers, avocados, ripe bananas, cured meats, many Oriental and prepared foods (read the labels!). Some people have been successful in treating their migraines with supplements of B-vitamins, particularly B6 and niacin. Children who are hyperactive may benefit from eliminating food additives, especially colorings, and foods high in salicylates trom their diets.The topic of this passage is ____________.

Tiếng Anh Tốt nghiệp THPT
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BỘ ĐỀ THI THPT QUỐC GIA CHUẨN CẤU TRÚC BỘ GIÁO DỤC MÔN TIẾNG ANH (P9)

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 23 to 27No one can say when sports began. Since it is impossible to (23) _____ a time when children did not spontaneously run races or wrestle, it is clear that children have always included sports in their play, but one can only speculate about the (24) _____ of sports as autotelic physical contests for adults. Hunters are depicted in prehistoric art, but it cannot be known (25) _____ the hunters pursued their prey in a mood of grim necessity or with the joyful abandon of sportsmen. It is certain, (26) ______, from the rich literary and iconographic evidence of all ancient civilizations that hunting soon became an end in itself at least for royalty and nobility. Archaeological evidence also indicates that ball games were common among ancient peoples as (27) _____as the Chinese and the Aztecs.Điền ô 27

Tiếng Anh Tốt nghiệp THPT
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BỘ ĐỀ THI THPT QUỐC GIA CHUẨN CẤU TRÚC BỘ GIÁO DỤC MÔN TIẾNG ANH (P9)

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 23 to 27No one can say when sports began. Since it is impossible to (23) _____ a time when children did not spontaneously run races or wrestle, it is clear that children have always included sports in their play, but one can only speculate about the (24) _____ of sports as autotelic physical contests for adults. Hunters are depicted in prehistoric art, but it cannot be known (25) _____ the hunters pursued their prey in a mood of grim necessity or with the joyful abandon of sportsmen. It is certain, (26) ______, from the rich literary and iconographic evidence of all ancient civilizations that hunting soon became an end in itself at least for royalty and nobility. Archaeological evidence also indicates that ball games were common among ancient peoples as (27) _____as the Chinese and the Aztecs.Điền ô 26

Tiếng Anh Tốt nghiệp THPT
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BỘ ĐỀ THI THPT QUỐC GIA CHUẨN CẤU TRÚC BỘ GIÁO DỤC MÔN TIẾNG ANH (P9)

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 23 to 27No one can say when sports began. Since it is impossible to (23) _____ a time when children did not spontaneously run races or wrestle, it is clear that children have always included sports in their play, but one can only speculate about the (24) _____ of sports as autotelic physical contests for adults. Hunters are depicted in prehistoric art, but it cannot be known (25) _____ the hunters pursued their prey in a mood of grim necessity or with the joyful abandon of sportsmen. It is certain, (26) ______, from the rich literary and iconographic evidence of all ancient civilizations that hunting soon became an end in itself at least for royalty and nobility. Archaeological evidence also indicates that ball games were common among ancient peoples as (27) _____as the Chinese and the Aztecs.Điền ô 25

Tiếng Anh Tốt nghiệp THPT
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Bài 23: Từ thông. Cảm ứng điện từ

Một khung dây hình vuông có cạnh dài 5cm, đặt trong từ trường đều có cảm ứng từ B=4.10-5T, mặt phẳng khung dây tạo với các đường sức từ một góc 30°. Từ thông qua mặt phẳng khung dây nhận giá trị nào sau đây?

Vật lý Lớp 11
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BỘ ĐỀ THI THPT QUỐC GIA CHUẨN CẤU TRÚC BỘ GIÁO DỤC MÔN TIẾNG ANH (P9)

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 23 to 27No one can say when sports began. Since it is impossible to (23) _____ a time when children did not spontaneously run races or wrestle, it is clear that children have always included sports in their play, but one can only speculate about the (24) _____ of sports as autotelic physical contests for adults. Hunters are depicted in prehistoric art, but it cannot be known (25) _____ the hunters pursued their prey in a mood of grim necessity or with the joyful abandon of sportsmen. It is certain, (26) ______, from the rich literary and iconographic evidence of all ancient civilizations that hunting soon became an end in itself at least for royalty and nobility. Archaeological evidence also indicates that ball games were common among ancient peoples as (27) _____as the Chinese and the Aztecs.Điền ô 24

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 4)

Một chất điểm tham gia đồng thời hai dao động điều hòa cùng phương, cùng tần số có phương trình lần lượt là x1=4sin(πt+α)cm và x2=43cos(πt)cm. Biên độ của dao động tổng hợp đạt giá trị lớn nhất khi

Vật lý Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 5)

Một nguồn phát sóng dao động điều hòa tạo ra sóng tròn đồng tâm O truyền trên mặt chất lỏng. Khoảng cách ngắn nhất giữa hai đỉnh sóng là 5 cm. Hai điểm M và N thuộc mặt chất lỏng mà phần tử chất lỏng tại đó dao động cùng pha với phần tử chất lỏng tại O. Không kể phần tử chất lỏng tại O, số phần tử chất lỏng dao động cùng pha với phần tử chất lỏng tại O trên đoạn thẳng MO là 6, trên đoạn thẳng NO là 4 và trên đoạn thẳng MN là 3. Khoảng cách MN lớn nhất có giá trị gần giá trị nào nhất sau đây?

Vật lý Tốt nghiệp THPT
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Đề minh họa đề thi Vật Lí cực hay có lời giải (Đề số 3)

Điều nào sau đây là sai khi nói về chuyển động thẳng đều?

Vật lý Tốt nghiệp THPT
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BỘ ĐỀ THI THPT QUỐC GIA CHUẨN CẤU TRÚC BỘ GIÁO DỤC MÔN TIẾNG ANH (P9)

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 23 to 27No one can say when sports began. Since it is impossible to (23) _____ a time when children did not spontaneously run races or wrestle, it is clear that children have always included sports in their play, but one can only speculate about the (24) _____ of sports as autotelic physical contests for adults. Hunters are depicted in prehistoric art, but it cannot be known (25) _____ the hunters pursued their prey in a mood of grim necessity or with the joyful abandon of sportsmen. It is certain, (26) ______, from the rich literary and iconographic evidence of all ancient civilizations that hunting soon became an end in itself at least for royalty and nobility. Archaeological evidence also indicates that ball games were common among ancient peoples as (27) _____as the Chinese and the Aztecs.Điền số 23

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 4)

Đặt vào hai đầu cuộn dây sơ cấp một máy biến áp lí tưởng ( bỏ qua hao phí) một điện áp xoay chiều giá trị hiệu dụng không đổi thì điện áp hiệu dụng giữa hai đầu cuộn thứ cấp để hở là 100V. Ở cuộn thứ cấp giảm bớt n vòng dây thì điện áp hiệu dụng giữa hai đầu để hở của nó là U, nếu tăng thêm n vòng dây thì điện áp đo là 2U. Nếu tăng thêm 3n vòng dây ở cuộn thứ cấp thì điện áp hiệu dụng giữa hai đầu để hở của cuộn dây này là

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Bài 23: Từ thông. Cảm ứng điện từ

Một khung dây hình vuông, cạnh dài 4cm, đặt trong từ trường đều có cảm ứng từ B=2.10-5T, các đường sức từ hợp với pháp tuyến của mặt phẳng khung dây góc 60°. Từ thông qua mặt phẳng khung dây là

Vật lý Lớp 11
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 4)

Kim loại làm ca tốt của một tế bào quang điện có giới hạn quang điện λ0. Lần lượt chiếu tới bề mặt catot hai bức xạ có bước sóng λ1 = 0,4 µm và λ2 = 0,5 µm thì vận tốc ban đầu cực đại của electron bắn ra khỏi bề mặt catot khác nhau 2 lần. Giá trị của λ0 là

Vật lý Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 4)

Mức năng lượng của nguyên tử Hidro có biểu thức En = -13,6/n2 (eV). Khi kích thích nguyên tử Hidro từ quỹ đạo dừng m lên quỹ đạo n bằng năng lượng 2,55eV, thấy bán kính quỹ đạo tăng 4 lần. Bước sóng nhỏ nhất mà nguyên tử Hidro có thể phát ra là

Vật lý Tốt nghiệp THPT
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Bài 23: Từ thông. Cảm ứng điện từ

Một khung dây hình tròn có diện tích S = 2cm2 đặt trong từ trường có cảm ứng từ B=5.10-2T, các đường sức từ vuông góc với mặt phẳng khung dây. Từ thông qua mặt phẳng khung dây là

Vật lý Lớp 11
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 4)

Sóng ngang có tần số f = 56Hz truyền từ đầu dây A của một sợi dây đàn hồi rất dài. Phần tử dây tại điểm M cách nguồn A một đoạn 50cm luôn dao động ngược pha với phần tử dây tại A. Biết tốc độ truyền sóng trên dây nằm trong khoảng từ 7m/s đến 10m/s. Tốc độ truyền sóng trên dây là

Vật lý Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 4)

Khi mắc điện trở R1 = 4Ω vào hai cực của một nguồn điện thì dòng điện trong mạch có cường độ I1 = 0,5A. Khi mắc điện trở R2 = 10Ω thì dòng điện trong mạch là I2 = 0,25A. Tính suất điện động E và điện trở trong r.

Vật lý Tốt nghiệp THPT
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Bài 23: Từ thông. Cảm ứng điện từ

Trường hợp nào sau đây từ thông qua vòng dây dẫn (C) biến thiên?

Vật lý Lớp 11
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Bài 23: Từ thông. Cảm ứng điện từ

Phát biểu nào sau đây không đúng với định luật Len-xơ về chiều dòng điện cảm ứng ?

Vật lý Lớp 11
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ĐỀ 19

Mark the letter A, B, C, or D on your answer sheet to indicate the word that differs from the other three in the position of the main stress in each of the following questions. 

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 5)

Đoạn mạch A, B được mắc nối tiếp theo thứ tự cuộn dây với hệ số tự cảm L=25πH biến trở R và tụ điện có điện dung C=10-225πF . Điểm M là điểm nằm giữa R và C. Nếu mắc vào hai đầu A, M một ắc quy có suất điện động 12 V và điện trở trong 4 Ω điều chỉnh R=R1 thì có dòng điện cường độ 0,1875 A. Mắc vào A, B một hiệu điện thế u=1202cos(100πt) V rồi điều chỉnh R=R2 thì công suất tiêu thụ trên biến trở đạt cực đại bằng 160 W. Tỷ số R1:R2 là

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Bài 23: Từ thông. Cảm ứng điện từ

Từ thông qua khung dây có diện tích S đặt trong từ trường đều đạt giá trị cực đại khi

Vật lý Lớp 11
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ĐỀ 19

Mark the letter A, B, C, or D on your answer sheet to indicate the word that differs from the other three in the position of the main stress in each of the following questions. 

Tiếng Anh Tốt nghiệp THPT
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ĐỀ 19

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

Tiếng Anh Tốt nghiệp THPT
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Bài 23: Từ thông. Cảm ứng điện từ

Cho một khung dây có điện tích S đặt trong từ trường đều, cảm ứng từ B→ , α là góc hợp bởi B→ và pháp tuyến của mặt phẳng khung dây. Công thức tính từ thông qua S là:

Vật lý Lớp 11
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 5)

Con lắc lò xo có độ cứng k, chiều dài l, một đầu gắn cố định, một đầu gắn vào vật có khối lượng m. Kích thích cho lò xo dao động điều hoà với biên độ A=12 trên mặt phẳng ngang không ma sát. Khi lò xo đang dao động và bị dãn cực đại, tiến hành giữ chặt lò xo tại vị trí cách vật 1 đoạn l, khi đó tốc độ dao động cực đại của vật là:

Vật lý Tốt nghiệp THPT
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ĐỀ 19

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

Tiếng Anh Tốt nghiệp THPT
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Bài 23: Từ thông. Cảm ứng điện từ

Đơn vị của từ thông có thể là

Vật lý Lớp 11
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Bài 23: Từ thông. Cảm ứng điện từ

Phát biểu nào sau đây không đúng?

Vật lý Lớp 11
Xem chi tiết 91.8 K lượt xem 6 năm trước
ĐỀ 18

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 questions from 44 to 50.Life originated in the early seas less than a billion years after Earth was formed. Yet another three billion years were to pass before the first plants and animals appeared on the continents. Life's transition from the sea to the land was perhaps as much of an evolutionary challenge as was the genesis of life.What forms of life were able to make such a drastic change in lifestyle? The traditional view of the first terrestrial organisms is based on mega fossils — relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive mega fossil record. Because of this, it has been commonly assumed that the sequence of terrestrialization reflected the evolution of modern terrestrial ecosystems. In this view, primitive vascular plants first colonized the margins of continental waters, followed by animals that fed on the plants, and lastly by animals that preyed on the plant-eaters. Moreover, the mega fossils suggest that terrestrial life appeared and diversified explosively near the boundary between the Silurian and the Devonian periods, a little more than 400 million years ago. Recently, however, paleontologists have been taking a closer look at the sediments below this Silurian-Devonian geological boundary. It turns out that some fossils can be extracted from these sediments by putting the rocks in an acid bath. The technique has uncovered new evidence from sediments that were deposited near the shores of the ancient oceans — plant microfossils and microscopic pieces of small animals. In many instances the specimens are less than one-tenth of a millimeter in diameter. Although they were entombed in the rocks for hundreds of millions of years, many of the fossils consist of the organic remains of the organism.These newly discovered fossils have not only revealed the existence of previously unknown organisms, but have also pushed back these dates for the invasion of land by multicellular organisms. Our views about the nature of the early plant and animal communities are now being revised. And with those revisions come new speculations about the first terrestrial life-forms.With which of the following conclusions would the author probably agree?

Tiếng Anh Tốt nghiệp THPT
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ĐỀ 18

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 questions from 44 to 50.Life originated in the early seas less than a billion years after Earth was formed. Yet another three billion years were to pass before the first plants and animals appeared on the continents. Life's transition from the sea to the land was perhaps as much of an evolutionary challenge as was the genesis of life.What forms of life were able to make such a drastic change in lifestyle? The traditional view of the first terrestrial organisms is based on mega fossils — relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive mega fossil record. Because of this, it has been commonly assumed that the sequence of terrestrialization reflected the evolution of modern terrestrial ecosystems. In this view, primitive vascular plants first colonized the margins of continental waters, followed by animals that fed on the plants, and lastly by animals that preyed on the plant-eaters. Moreover, the mega fossils suggest that terrestrial life appeared and diversified explosively near the boundary between the Silurian and the Devonian periods, a little more than 400 million years ago. Recently, however, paleontologists have been taking a closer look at the sediments below this Silurian-Devonian geological boundary. It turns out that some fossils can be extracted from these sediments by putting the rocks in an acid bath. The technique has uncovered new evidence from sediments that were deposited near the shores of the ancient oceans — plant microfossils and microscopic pieces of small animals. In many instances the specimens are less than one-tenth of a millimeter in diameter. Although they were entombed in the rocks for hundreds of millions of years, many of the fossils consist of the organic remains of the organism.These newly discovered fossils have not only revealed the existence of previously unknown organisms, but have also pushed back these dates for the invasion of land by multicellular organisms. Our views about the nature of the early plant and animal communities are now being revised. And with those revisions come new speculations about the first terrestrial life-forms.Which of the following resulted from the discovery of microscopic fossils?

Tiếng Anh Tốt nghiệp THPT
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Bài 23: Từ thông. Cảm ứng điện từ

Phát biểu nào sau đây không đúng khi nói về từ thông ?

Vật lý Lớp 11
Xem chi tiết 100.3 K lượt xem 6 năm trước
ĐỀ 18

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 questions from 44 to 50.Life originated in the early seas less than a billion years after Earth was formed. Yet another three billion years were to pass before the first plants and animals appeared on the continents. Life's transition from the sea to the land was perhaps as much of an evolutionary challenge as was the genesis of life.What forms of life were able to make such a drastic change in lifestyle? The traditional view of the first terrestrial organisms is based on mega fossils — relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive mega fossil record. Because of this, it has been commonly assumed that the sequence of terrestrialization reflected the evolution of modern terrestrial ecosystems. In this view, primitive vascular plants first colonized the margins of continental waters, followed by animals that fed on the plants, and lastly by animals that preyed on the plant-eaters. Moreover, the mega fossils suggest that terrestrial life appeared and diversified explosively near the boundary between the Silurian and the Devonian periods, a little more than 400 million years ago. Recently, however, paleontologists have been taking a closer look at the sediments below this Silurian-Devonian geological boundary. It turns out that some fossils can be extracted from these sediments by putting the rocks in an acid bath. The technique has uncovered new evidence from sediments that were deposited near the shores of the ancient oceans — plant microfossils and microscopic pieces of small animals. In many instances the specimens are less than one-tenth of a millimeter in diameter. Although they were entombed in the rocks for hundreds of millions of years, many of the fossils consist of the organic remains of the organism.These newly discovered fossils have not only revealed the existence of previously unknown organisms, but have also pushed back these dates for the invasion of land by multicellular organisms. Our views about the nature of the early plant and animal communities are now being revised. And with those revisions come new speculations about the first terrestrial life-forms.The word “entombed” in lime 22 is closest in meaning to

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 5)

Cho mạch điện có sơ đồ như hình bên: ξ=12V; R1=4Ω; R2=R3=10Ω.Bỏ qua điện trở của ampe kế A và dây nối. Số chỉ của ampe kế là 0,6 A. Giá trị điện trở trong r của nguồn điện là

Vật lý Tốt nghiệp THPT
Xem chi tiết 364 lượt xem 6 năm trước
ĐỀ 18

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 questions from 44 to 50.Life originated in the early seas less than a billion years after Earth was formed. Yet another three billion years were to pass before the first plants and animals appeared on the continents. Life's transition from the sea to the land was perhaps as much of an evolutionary challenge as was the genesis of life.What forms of life were able to make such a drastic change in lifestyle? The traditional view of the first terrestrial organisms is based on mega fossils — relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive mega fossil record. Because of this, it has been commonly assumed that the sequence of terrestrialization reflected the evolution of modern terrestrial ecosystems. In this view, primitive vascular plants first colonized the margins of continental waters, followed by animals that fed on the plants, and lastly by animals that preyed on the plant-eaters. Moreover, the mega fossils suggest that terrestrial life appeared and diversified explosively near the boundary between the Silurian and the Devonian periods, a little more than 400 million years ago. Recently, however, paleontologists have been taking a closer look at the sediments below this Silurian-Devonian geological boundary. It turns out that some fossils can be extracted from these sediments by putting the rocks in an acid bath. The technique has uncovered new evidence from sediments that were deposited near the shores of the ancient oceans — plant microfossils and microscopic pieces of small animals. In many instances the specimens are less than one-tenth of a millimeter in diameter. Although they were entombed in the rocks for hundreds of millions of years, many of the fossils consist of the organic remains of the organism.These newly discovered fossils have not only revealed the existence of previously unknown organisms, but have also pushed back these dates for the invasion of land by multicellular organisms. Our views about the nature of the early plant and animal communities are now being revised. And with those revisions come new speculations about the first terrestrial life-forms.The word “they” in line 22 refers to

Tiếng Anh Tốt nghiệp THPT
Xem chi tiết 1.3 K lượt xem 6 năm trước
ĐỀ 18

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 questions from 44 to 50.Life originated in the early seas less than a billion years after Earth was formed. Yet another three billion years were to pass before the first plants and animals appeared on the continents. Life's transition from the sea to the land was perhaps as much of an evolutionary challenge as was the genesis of life.What forms of life were able to make such a drastic change in lifestyle? The traditional view of the first terrestrial organisms is based on mega fossils — relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive mega fossil record. Because of this, it has been commonly assumed that the sequence of terrestrialization reflected the evolution of modern terrestrial ecosystems. In this view, primitive vascular plants first colonized the margins of continental waters, followed by animals that fed on the plants, and lastly by animals that preyed on the plant-eaters. Moreover, the mega fossils suggest that terrestrial life appeared and diversified explosively near the boundary between the Silurian and the Devonian periods, a little more than 400 million years ago. Recently, however, paleontologists have been taking a closer look at the sediments below this Silurian-Devonian geological boundary. It turns out that some fossils can be extracted from these sediments by putting the rocks in an acid bath. The technique has uncovered new evidence from sediments that were deposited near the shores of the ancient oceans — plant microfossils and microscopic pieces of small animals. In many instances the specimens are less than one-tenth of a millimeter in diameter. Although they were entombed in the rocks for hundreds of millions of years, many of the fossils consist of the organic remains of the organism.These newly discovered fossils have not only revealed the existence of previously unknown organisms, but have also pushed back these dates for the invasion of land by multicellular organisms. Our views about the nature of the early plant and animal communities are now being revised. And with those revisions come new speculations about the first terrestrial life-forms.What can be inferred from the passage about the fossils mentioned in lines 17-20?

Tiếng Anh Tốt nghiệp THPT
Xem chi tiết 1.4 K lượt xem 6 năm trước
ĐỀ 18

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 questions from 44 to 50.Life originated in the early seas less than a billion years after Earth was formed. Yet another three billion years were to pass before the first plants and animals appeared on the continents. Life's transition from the sea to the land was perhaps as much of an evolutionary challenge as was the genesis of life.What forms of life were able to make such a drastic change in lifestyle? The traditional view of the first terrestrial organisms is based on mega fossils — relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive mega fossil record. Because of this, it has been commonly assumed that the sequence of terrestrialization reflected the evolution of modern terrestrial ecosystems. In this view, primitive vascular plants first colonized the margins of continental waters, followed by animals that fed on the plants, and lastly by animals that preyed on the plant-eaters. Moreover, the mega fossils suggest that terrestrial life appeared and diversified explosively near the boundary between the Silurian and the Devonian periods, a little more than 400 million years ago. Recently, however, paleontologists have been taking a closer look at the sediments below this Silurian-Devonian geological boundary. It turns out that some fossils can be extracted from these sediments by putting the rocks in an acid bath. The technique has uncovered new evidence from sediments that were deposited near the shores of the ancient oceans — plant microfossils and microscopic pieces of small animals. In many instances the specimens are less than one-tenth of a millimeter in diameter. Although they were entombed in the rocks for hundreds of millions of years, many of the fossils consist of the organic remains of the organism.These newly discovered fossils have not only revealed the existence of previously unknown organisms, but have also pushed back these dates for the invasion of land by multicellular organisms. Our views about the nature of the early plant and animal communities are now being revised. And with those revisions come new speculations about the first terrestrial life-forms.According to the passage, what happened about 400 million years ago?

Tiếng Anh Tốt nghiệp THPT
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ĐỀ 18

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 questions from 44 to 50.Life originated in the early seas less than a billion years after Earth was formed. Yet another three billion years were to pass before the first plants and animals appeared on the continents. Life's transition from the sea to the land was perhaps as much of an evolutionary challenge as was the genesis of life.What forms of life were able to make such a drastic change in lifestyle? The traditional view of the first terrestrial organisms is based on mega fossils — relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive mega fossil record. Because of this, it has been commonly assumed that the sequence of terrestrialization reflected the evolution of modern terrestrial ecosystems. In this view, primitive vascular plants first colonized the margins of continental waters, followed by animals that fed on the plants, and lastly by animals that preyed on the plant-eaters. Moreover, the mega fossils suggest that terrestrial life appeared and diversified explosively near the boundary between the Silurian and the Devonian periods, a little more than 400 million years ago. Recently, however, paleontologists have been taking a closer look at the sediments below this Silurian-Devonian geological boundary. It turns out that some fossils can be extracted from these sediments by putting the rocks in an acid bath. The technique has uncovered new evidence from sediments that were deposited near the shores of the ancient oceans — plant microfossils and microscopic pieces of small animals. In many instances the specimens are less than one-tenth of a millimeter in diameter. Although they were entombed in the rocks for hundreds of millions of years, many of the fossils consist of the organic remains of the organism.These newly discovered fossils have not only revealed the existence of previously unknown organisms, but have also pushed back these dates for the invasion of land by multicellular organisms. Our views about the nature of the early plant and animal communities are now being revised. And with those revisions come new speculations about the first terrestrial life-forms.According to the theory that the author calls “the traditional view,” what was the first form of life to appear on land?

Tiếng Anh Tốt nghiệp THPT
Xem chi tiết 431 lượt xem 6 năm trước
ĐỀ 18

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 questions from 44 to 50.Life originated in the early seas less than a billion years after Earth was formed. Yet another three billion years were to pass before the first plants and animals appeared on the continents. Life's transition from the sea to the land was perhaps as much of an evolutionary challenge as was the genesis of life.What forms of life were able to make such a drastic change in lifestyle? The traditional view of the first terrestrial organisms is based on mega fossils — relatively large specimens of essentially whole plants and animals. Vascular plants, related to modern seed plants and ferns, left the first comprehensive mega fossil record. Because of this, it has been commonly assumed that the sequence of terrestrialization reflected the evolution of modern terrestrial ecosystems. In this view, primitive vascular plants first colonized the margins of continental waters, followed by animals that fed on the plants, and lastly by animals that preyed on the plant-eaters. Moreover, the mega fossils suggest that terrestrial life appeared and diversified explosively near the boundary between the Silurian and the Devonian periods, a little more than 400 million years ago. Recently, however, paleontologists have been taking a closer look at the sediments below this Silurian-Devonian geological boundary. It turns out that some fossils can be extracted from these sediments by putting the rocks in an acid bath. The technique has uncovered new evidence from sediments that were deposited near the shores of the ancient oceans — plant microfossils and microscopic pieces of small animals. In many instances the specimens are less than one-tenth of a millimeter in diameter. Although they were entombed in the rocks for hundreds of millions of years, many of the fossils consist of the organic remains of the organism.These newly discovered fossils have not only revealed the existence of previously unknown organisms, but have also pushed back these dates for the invasion of land by multicellular organisms. Our views about the nature of the early plant and animal communities are now being revised. And with those revisions come new speculations about the first terrestrial life-forms. The word “drastic” in line 5 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 22)

Mark the letter A, B, C or D on your answer sheet to indicate the word(s) OPPOSITE in the meaning to the underlined word(s) in each of the following questionsLunar years were inconvenient for agricultural purposes

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi thử THPTQG môn Vật Lí cực hay có lời giải (Đề số 5)

Trong mạch dao động LC lý đang có dao động điện từ tự do với tần số góc 104 rad/s. Điện tích cực đại trên tụ điện là 1,0 nC. Khi cường độ dòng điện trong mạch bằng 6,0 μA thì điện tích trên bản tụ là

Vật lý Tốt nghiệp THPT
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Đề thi thử THPTGQ môn Toán cực cực hay có lời giải chi tiết(Đề 6)

Thể tích V của khối tròn xoay khi cho hình phẳng H giới hạn bởi các đường y=1-x2 và y=x2-1 quay quanh trục Ox được xác định bởi công thức nào sau đây?

Toán Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 22)

Mark the letter A, B, C or D on your answer sheet to indicate the word(s) OPPOSITE in the meaning to the underlined word(s) in each of the following questionsDesigners could move away from conservative styles and promote the swimsuits that revealed a body’s physical attributes

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 22)

_______ , let me know

Tiếng Anh Tốt nghiệp THPT
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Đề thi thử THPTGQ môn Toán cực cực hay có lời giải chi tiết(Đề 6)

Tính diện tích hình phẳng được tô đậm ở hình bên.

Toán Tốt nghiệp THPT
Xem chi tiết 3.7 K lượt xem 6 năm trước

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