Hệ số căng bề mặt của nước là α = 74.10⁻³ (N/m) có nghĩa là

Read the following pasage and mark the letter A, B, C or D to indicate the correct answer to each of the questions:

 In science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. 

 A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected.

 Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." 

 Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hypothesis is a leap into the unknown. It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. 

Question: In the last paragraph, what does the author imply is a major function of hypotheses?         

Read the following passage and mark the letters A, B, C or D on your answer sheet to indicate the correct answer to each of the questions: 

This rapid transcontinental settlement and these new urban industrial circumstances of the last half of the 19th century were accompanied by the development of national literature of great abundance and variety. New themes, new forms, new subjects, new regions, new authors, new audiences all emerged in the literature of this half century.

As a result, at the onset of World War I, the spirit and substance of American literature had evolved remarkably, just as its center of production had shifted from Boston to New York in the late 1880s and the sources of its energy to Chicago and the Midwest. No longer was it produced, at least in its popular forms, in the main by solemn, typically moralistic men from New England and the Old South; no longer were polite, well-dressed, grammatically correct, middle-class young people the only central characters in its narratives; no longer were these narratives to be set in exotic places and remote times; no longer, indeed, were fiction, poetry, drama, and formal history the chief acceptable forms of literary expression; no longer, finally, was literature read primarily by young, middle class women.

In sum, American literature in these years fulfilled in considerable measure the condition Walt Whitman called for in 1867 in describing Leaves of Grass: it treats, he said of his own major work, each state and region as peers "and expands from them, and includes the world ... connecting an American citizen with the citizens of all nations." At the same time, these years saw the emergence of what has been designated "the literature of argument," powerful works in sociology, philosophy, psychology, many of them impelled by the spirit of exposure and reform. Just as America learned to play a role in this half century as an autonomous international political, economic, and military power, so did its literature establish itself as a producer of major works.

Question: The word “exotic" in paragraph two is closest in meaning to________.    

Read the following passage and mark the letters A, B, C or D on your answer sheet to indicate the correct answer to each of the questions: 

This rapid transcontinental settlement and these new urban industrial circumstances of the last half of the 19th century were accompanied by the development of national literature of great abundance and variety. New themes, new forms, new subjects, new regions, new authors, new audiences all emerged in the literature of this half century.

As a result, at the onset of World War I, the spirit and substance of American literature had evolved remarkably, just as its center of production had shifted from Boston to New York in the late 1880s and the sources of its energy to Chicago and the Midwest. No longer was it produced, at least in its popular forms, in the main by solemn, typically moralistic men from New England and the Old South; no longer were polite, well-dressed, grammatically correct, middle-class young people the only central characters in its narratives; no longer were these narratives to be set in exotic places and remote times; no longer, indeed, were fiction, poetry, drama, and formal history the chief acceptable forms of literary expression; no longer, finally, was literature read primarily by young, middle class women.

In sum, American literature in these years fulfilled in considerable measure the condition Walt Whitman called for in 1867 in describing Leaves of Grass: it treats, he said of his own major work, each state and region as peers "and expands from them, and includes the world ... connecting an American citizen with the citizens of all nations". At the same time, these years saw the emergence of what has been designated "the literature of argument," powerful works in sociology, philosophy, psychology, many of them impelled by the spirit of exposure and reform. Just as America learned to play a role in this half century as an autonomous international political, economic, and military power, so did its literature establish itself as a producer of major works.

Question: The word “evolved” in paragraph two is closest in meaning to________.      

Read the following passage and mark the letters A, B, C or D on your answer sheet to indicate the correct answer to each of the questions: 

This rapid transcontinental settlement and these new urban industrial circumstances of the last half of the 19th century were accompanied by the development of national literature of great abundance and variety. New themes, new forms, new subjects, new regions, new authors, new audiences all emerged in the literature of this half century.

As a result, at the onset of World War I, the spirit and substance of American literature had evolved remarkably, just as its center of production had shifted from Boston to New York in the late 1880s and the sources of its energy to Chicago and the Midwest. No longer was it produced, at least in its popular forms, in the main by solemn, typically moralistic men from New England and the Old South; no longer were polite, well-dressed, grammatically correct, middle-class young people the only central characters in its narratives; no longer were these narratives to be set in exotic places and remote times; no longer, indeed, were fiction, poetry, drama, and formal history the chief acceptable forms of literary expression; no longer, finally, was literature read primarily by young, middle class women.

In sum, American literature in these years fulfilled in considerable measure the condition Walt Whitman called for in 1867 in describing Leaves of Grass: it treats, he said of his own major work, each state and region as peers "and expands from them, and includes the world ... connecting an American citizen with the citizens of all nations." At the same time, these years saw the emergence of what has been designated "the literature of argument," powerful works in sociology, philosophy, psychology, many of them impelled by the spirit of exposure and reform. Just as America learned to play a role in this half century as an autonomous international political, economic, and military power, so did its literature establish itself as a producer of major works.

Question: It can be inferred from the passage that the previous passage probably discussed________.  

Read the following passage and mark the letters A, B, C or D on your answer sheet to indicate the correct answer to each of the questions: 

This rapid transcontinental settlement and these new urban industrial circumstances of the last half of the 19th century were accompanied by the development of national literature of great abundance and variety. New themes, new forms, new subjects, new regions, new authors, new audiences all emerged in the literature of this half century.

As a result, at the onset of World War I, the spirit and substance of American literature had evolved remarkably, just as its center of production had shifted from Boston to New York in the late 1880s and the sources of its energy to Chicago and the Midwest. No longer was it produced, at least in its popular forms, in the main by solemn, typically moralistic men from New England and the Old South; no longer were polite, well-dressed, grammatically correct, middle-class young people the only central characters in its narratives; no longer were these narratives to be set in exotic places and remote times; no longer, indeed, were fiction, poetry, drama, and formal history the chief acceptable forms of literary expression; no longer, finally, was literature read primarily by young, middle class women.

In sum, American literature in these years fulfilled in considerable measure the condition Walt Whitman called for in 1867 in describing Leaves of Grass: it treats, he said of his own major work, each state and region as peers "and expands from them, and includes the world ... connecting an American citizen with the citizens of all nations." At the same time, these years saw the emergence of what has been designated "the literature of argument," powerful works in sociology, philosophy, psychology, many of them impelled by the spirit of exposure and reform. Just as America learned to play a role in this half century as an autonomous international political, economic, and military power, so did its literature establish itself as a producer of major works.

Question: The main idea of this passage is________.  

Read the following passage and mark the letters A, B, C or D on your answer sheet to indicate the correct answer to each of the questions:

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 from their diets. A few of these are almonds, green peppers, peaches, tea, grapes. This is the diet made popular by Benjamin Feingold, who has written the book “Why your Child is Hyperactive”. Other researchers have had mixed results when testing whether the diet is effective.

Question 42: The author states that the reason that infants need to avoid certain foods related to allergies has to do with the infant's______________.    

Read the following passage and mark the letters A, B, C or D on your answer sheet to indicate the correct answer to each of the questions:

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 from their diets. A few of these are almonds, green peppers, peaches, tea, grapes. This is the diet made popular by Benjamin Feingold, who has written the book “Why your Child is Hyperactive”. Other researchers have had mixed results when testing whether the diet is effective.

Question: The word "hyperactive" is closest in meaning to______________.  

Read the following passage and mark the letters A, B, C or D on your answer sheet to indicate the correct answer to each of the questions:

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 from their diets. A few of these are almonds, green peppers, peaches, tea, grapes. This is the diet made popular by Benjamin Feingold, who has written the book “Why your Child is Hyperactive”. Other researchers have had mixed results when testing whether the diet is effective.

Question: What can be inferred about babies from this passage?  

Read the following passage and mark the letters A, B, C or D on your answer sheet to indicate the correct answer to each of the questions: 

This rapid transcontinental settlement and these new urban industrial circumstances of the last half of the 19th century were accompanied by the development of national literature of great abundance and variety. New themes, new forms, new subjects, new regions, new authors, new audiences all emerged in the literature of this half century.

As a result, at the onset of World War I, the spirit and substance of American literature had evolved remarkably, just as its center of production had shifted from Boston to New York in the late 1880s and the sources of its energy to Chicago and the Midwest. No longer was it produced, at least in its popular forms, in the main by solemn, typically moralistic men from New England and the Old South; no longer were polite, well-dressed, grammatically correct, middle-class young people the only central characters in its narratives; no longer were these narratives to be set in exotic places and remote times; no longer, indeed, were fiction, poetry, drama, and formal history the chief acceptable forms of literary expression; no longer, finally, was literature read primarily by young, middle class women.

In sum, American literature in these years fulfilled in considerable measure the condition Walt Whitman called for in 1867 in describing Leaves of Grass: it treats, he said of his own major work, each state and region as peers "and expands from them, and includes the world ... connecting an American citizen with the citizens of all nations." At the same time, these years saw the emergence of what has been designated "the literature of argument," powerful works in sociology, philosophy, psychology, many of them impelled by the spirit of exposure and reform. Just as America learned to play a role in this half century as an autonomous international political, economic, and military power, so did its literature establish itself as a producer of major works.

Question : The phrase “these years” in the third paragraph refers to________.    

Read the following passage and mark the letters A, B, C or D on your answer sheet to indicate the correct answer to each of the questions: 

This rapid transcontinental settlement and these new urban industrial circumstances of the last half of the 19th century were accompanied by the development of national literature of great abundance and variety. New themes, new forms, new subjects, new regions, new authors, new audiences all emerged in the literature of this half century.

As a result, at the onset of World War I, the spirit and substance of American literature had evolved remarkably, just as its center of production had shifted from Boston to New York in the late 1880s and the sources of its energy to Chicago and the Midwest. No longer was it produced, at least in its popular forms, in the main by solemn, typically moralistic men from New England and the Old South; no longer were polite, well-dressed, grammatically correct, middle-class young people the only central characters in its narratives; no longer were these narratives to be set in exotic places and remote times; no longer, indeed, were fiction, poetry, drama, and formal history the chief acceptable forms of literary expression; no longer, finally, was literature read primarily by young, middle class women.

In sum, American literature in these years fulfilled in considerable measure the condition Walt Whitman called for in 1867 in describing Leaves of Grass: it treats, he said of his own major work, each state and region as peers "and expands from them, and includes the world ... connecting an American citizen with the citizens of all nations." At the same time, these years saw the emergence of what has been designated "the literature of argument," powerful works in sociology, philosophy, psychology, many of them impelled by the spirit of exposure and reform. Just as America learned to play a role in this half century as an autonomous international political, economic, and military power, so did its literature establish itself as a producer of major works.

Question: The author uses the word “indeed” in the second paragraph for what purpose?