Khi một chất điểm dao động điều hòa tới vị trí cân bằng thì:

Question 44: The phrase "broke out" in the second paragraph is closest in meaning to

Clara Barton became known as “The Angel of the Battlefield” during the American Civil War. Born in Oxford, Massachusetts in 1821, Clara Barton’s interest in helping soldiers on the battlefield began when she was told army stories from her father. Another event that influenced her decision to help soldiers was an accident her brother had. His injuries were cared for by Barton for 2 years. At the time, she was only 11 years old. Barton began teaching school at the age of 15. She taught for 18 years before she moved to Washington, D.C. in 1854. The civil war broke out 6 years later. Immediately, Barton started war service by helping the soldiers with their needs. At the battle of Bull Run, Clara Barton received permission from the government to take care of the sick and hurt. Barton did this with great empathy and kindness. She acknowledged each soldier as a person. Her endurance and courage on the battlefield were admired by many. When the war ended in 1865, she used 4 years of her life to assist the government in searching for soldiers who were missing during the war. The search for missing soldiers and years of hard work made her feeble physically. In 1869, her doctors recommended a trip to Europe for a rest. While she was on vacation, she became involved with the International Red Cross, an organization set up by the Geneva Convention in 1864. Clara Barton realized that the Red Cross would be a big help to the United States. After she returned to the United States, she worked very hard to create an American Red Cross. She talked to government leaders and let American people know about the Red Cross. In 1881, the National Society of the Red Cross was finally established with its headquarters in Washington, D.C. Clara Barton managed its activities for 23 years. Barton never let her age stop her from helping people. At the age of 79, she helped flood victims in Galveston, Texas. Barton finally resigned from the Red Cross in 1904. She was 92 years old and had truly earned her titled “The Angel of the Battlefield”.          

Question 47: What can be inferred about the government? 

Clara Barton became known as “The Angel of the Battlefield” during the American Civil War. Born in Oxford, Massachusetts in 1821, Clara Barton’s interest in helping soldiers on the battlefield began when she was told army stories from her father. Another event that influenced her decision to help soldiers was an accident her brother had. His injuries were cared for by Barton for 2 years. At the time, she was only 11 years old. Barton began teaching school at the age of 15. She taught for 18 years before she moved to Washington, D.C. in 1854. The civil war broke out 6 years later. Immediately, Barton started war service by helping the soldiers with their needs. At the battle of Bull Run, Clara Barton received permission from the government to take care of the sick and hurt. Barton did this with great empathy and kindness. She acknowledged each soldier as a person. Her endurance and courage on the battlefield were admired by many. When the war ended in 1865, she used 4 years of her life to assist the government in searching for soldiers who were missing during the war. The search for missing soldiers and years of hard work made her feeble physically. In 1869, her doctors recommended a trip to Europe for a rest. While she was on vacation, she became involved with the International Red Cross, an organization set up by the Geneva Convention in 1864. Clara Barton realized that the Red Cross would be a big help to the United States. After she returned to the United States, she worked very hard to create an American Red Cross. She talked to government leaders and let American people know about the Red Cross. In 1881, the National Society of the Red Cross was finally established with its headquarters in Washington, D.C. Clara Barton managed its activities for 23 years. Barton never let her age stop her from helping people. At the age of 79, she helped flood victims in Galveston, Texas. Barton finally resigned from the Red Cross in 1904. She was 92 years old and had truly earned her titled “The Angel of the Battlefield”.    

Question 48: What does the author mention about the American Red Cross?

Clara Barton became known as “The Angel of the Battlefield” during the American Civil War. Born in Oxford, Massachusetts in 1821, Clara Barton’s interest in helping soldiers on the battlefield began when she was told army stories from her father. Another event that influenced her decision to help soldiers was an accident her brother had. His injuries were cared for by Barton for 2 years. At the time, she was only 11 years old. Barton began teaching school at the age of 15. She taught for 18 years before she moved to Washington, D.C. in 1854. The civil war broke out 6 years later. Immediately, Barton started war service by helping the soldiers with their needs. At the battle of Bull Run, Clara Barton received permission from the government to take care of the sick and hurt. Barton did this with great empathy and kindness. She acknowledged each soldier as a person. Her endurance and courage on the battlefield were admired by many. When the war ended in 1865, she used 4 years of her life to assist the government in searching for soldiers who were missing during the war. The search for missing soldiers and years of hard work made her feeble physically. In 1869, her doctors recommended a trip to Europe for a rest. While she was on vacation, she became involved with the International Red Cross, an organization set up by the Geneva Convention in 1864. Clara Barton realized that the Red Cross would be a big help to the United States. After she returned to the United States, she worked very hard to create an American Red Cross. She talked to government leaders and let American people know about the Red Cross. In 1881, the National Society of the Red Cross was finally established with its headquarters in Washington, D.C. Clara Barton managed its activities for 23 years. Barton never let her age stop her from helping people. At the age of 79, she helped flood victims in Galveston, Texas. Barton finally resigned from the Red Cross in 1904. She was 92 years old and had truly earned her titled “The Angel of the Battlefield”.    

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:

By the mid-nineteenth century, the term "icebox" had entered the American language, but ice was still only beginning to affect the diet of ordinary citizens in the United States. The ice trade grew with the growth of cities. Ice was used in hotels, taverns, and hospitals, and by some forward-looking city dealers in fresh meat, fresh fish, and butter. After the Civil War (1860-1865), as ice was used to refrigerate freight cars, it also came into household use. Even before 1880, half the ice sold in New York, Philadelphia, and Baltimore, and one-third of that sold in Boston and Chicago, went to families for their own use. This had become possible because a new household convenience, the icebox, a precursor of the modern refrigerator, had been invented. Making an efficient icebox was not as easy as we might now suppose. In the early nineteenth century, the knowledge of the physics of heat, which was essential to a science of refrigeration, was rudimentary. The common-sense notion that the best icebox was one that prevented the ice from melting was of course mistaken, for it was the melting of the ice that performed the cooling. Nevertheless, early efforts to economize ice included wrapping the ice in blankets, which kept the ice from doing its job. Not until near the end of the nineteenth century did inventors achieve the nice balance of insulation and circulation needed for an efficient icebox. But as early as 1803, an ingenious Maryland farmer, Thomas Moore, had been on the right track. He owned a farm about twenty miles outside the city of Washington, for which the village of Georgetown was the market center. When he used an icebox of his own design to transport his butter to market, he found that customers would pass up the rapidly melting stuff in the tubs of his competitors to pay a premium price for his butter, still fresh and hard in neat, one-pound bricks. One advantage of his icebox, Moore explained, was that farmers would no longer have to travel to market at night in order to keep their produce cool.  

Question: The "produce" mentioned in the last paragraph could include _____________.         

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:

By the mid-nineteenth century, the term "icebox" had entered the American language, but ice was still only beginning to affect the diet of ordinary citizens in the United States. The ice trade grew with the growth of cities. Ice was used in hotels, taverns, and hospitals, and by some forward-looking city dealers in fresh meat, fresh fish, and butter. After the Civil War (1860-1865), as ice was used to refrigerate freight cars, it also came into household use. Even before 1880, half the ice sold in New York, Philadelphia, and Baltimore, and one-third of that sold in Boston and Chicago, went to families for their own use. This had become possible because a new household convenience, the icebox, a precursor of the modern refrigerator, had been invented. Making an efficient icebox was not as easy as we might now suppose. In the early nineteenth century, the knowledge of the physics of heat, which was essential to a science of refrigeration, was rudimentary. The common-sense notion that the best icebox was one that prevented the ice from melting was of course mistaken, for it was the melting of the ice that performed the cooling. Nevertheless, early efforts to economize ice included wrapping the ice in blankets, which kept the ice from doing its job. Not until near the end of the nineteenth century did inventors achieve the nice balance of insulation and circulation needed for an efficient icebox. But as early as 1803, an ingenious Maryland farmer, Thomas Moore, had been on the right track. He owned a farm about twenty miles outside the city of Washington, for which the village of Georgetown was the market center. When he used an icebox of his own design to transport his butter to market, he found that customers would pass up the rapidly melting stuff in the tubs of his competitors to pay a premium price for his butter, still fresh and hard in neat, one-pound bricks. One advantage of his icebox, Moore explained, was that farmers would no longer have to travel to market at night in order to keep their produce cool.  

Question: The author describes Thomas Moore as having been "on the right track" to indicate that ______________.         

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:

By the mid-nineteenth century, the term "icebox" had entered the American language, but ice was still only beginning to affect the diet of ordinary citizens in the United States. The ice trade grew with the growth of cities. Ice was used in hotels, taverns, and hospitals, and by some forward-looking city dealers in fresh meat, fresh fish, and butter. After the Civil War (1860-1865), as ice was used to refrigerate freight cars, it also came into household use. Even before 1880, half the ice sold in New York, Philadelphia, and Baltimore, and one-third of that sold in Boston and Chicago, went to families for their own use. This had become possible because a new household convenience, the icebox, a precursor of the modern refrigerator, had been invented. Making an efficient icebox was not as easy as we might now suppose. In the early nineteenth century, the knowledge of the physics of heat, which was essential to a science of refrigeration, was rudimentary. The common-sense notion that the best icebox was one that prevented the ice from melting was of course mistaken, for it was the melting of the ice that performed the cooling. Nevertheless, early efforts to economize ice included wrapping the ice in blankets, which kept the ice from doing its job. Not until near the end of the nineteenth century did inventors achieve the nice balance of insulation and circulation needed for an efficient icebox. But as early as 1803, an ingenious Maryland farmer, Thomas Moore, had been on the right track. He owned a farm about twenty miles outside the city of Washington, for which the village of Georgetown was the market center. When he used an icebox of his own design to transport his butter to market, he found that customers would pass up the rapidly melting stuff in the tubs of his competitors to pay a premium price for his butter, still fresh and hard in neat, one-pound bricks. One advantage of his icebox, Moore explained, was that farmers would no longer have to travel to market at night in order to keep their produce cool.  

Question: According to the passage, Moore's icebox allowed him to _______________.         

  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:

By the mid-nineteenth century, the term "icebox" had entered the American language, but ice was still only beginning to affect the diet of ordinary citizens in the United States. The ice trade grew with the growth of cities. Ice was used in hotels, taverns, and hospitals, and by some forward-looking city dealers in fresh meat, fresh fish, and butter. After the Civil War (1860-1865), as ice was used to refrigerate freight cars, it also came into household use. Even before 1880, half the ice sold in New York, Philadelphia, and Baltimore, and one-third of that sold in Boston and Chicago, went to families for their own use. This had become possible because a new household convenience, the icebox, a precursor of the modern refrigerator, had been invented. Making an efficient icebox was not as easy as we might now suppose. In the early nineteenth century, the knowledge of the physics of heat, which was essential to a science of refrigeration, was rudimentary. The common-sense notion that the best icebox was one that prevented the ice from melting was of course mistaken, for it was the melting of the ice that performed the cooling. Nevertheless, early efforts to economize ice included wrapping the ice in blankets, which kept the ice from doing its job. Not until near the end of the nineteenth century did inventors achieve the nice balance of insulation and circulation needed for an efficient icebox. But as early as 1803, an ingenious Maryland farmer, Thomas Moore, had been on the right track. He owned a farm about twenty miles outside the city of Washington, for which the village of Georgetown was the market center. When he used an icebox of his own design to transport his butter to market, he found that customers would pass up the rapidly melting stuff in the tubs of his competitors to pay a premium price for his butter, still fresh and hard in neat, one-pound bricks. One advantage of his icebox, Moore explained, was that farmers would no longer have to travel to market at night in order to keep their produce cool.

Question: According to the passage, which of the following was an obstacle to the development of the icebox?         

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:

By the mid-nineteenth century, the term "icebox" had entered the American language, but ice was still only beginning to affect the diet of ordinary citizens in the United States. The ice trade grew with the growth of cities. Ice was used in hotels, taverns, and hospitals, and by some forward-looking city dealers in fresh meat, fresh fish, and butter. After the Civil War (1860-1865), as ice was used to refrigerate freight cars, it also came into household use. Even before 1880, half the ice sold in New York, Philadelphia, and Baltimore, and one-third of that sold in Boston and Chicago, went to families for their own use. This had become possible because a new household convenience, the icebox, a precursor of the modern refrigerator, had been invented. Making an efficient icebox was not as easy as we might now suppose. In the early nineteenth century, the knowledge of the physics of heat, which was essential to a science of refrigeration, was rudimentary. The common-sense notion that the best icebox was one that prevented the ice from melting was of course mistaken, for it was the melting of the ice that performed the cooling. Nevertheless, early efforts to economize ice included wrapping the ice in blankets, which kept the ice from doing its job. Not until near the end of the nineteenth century did inventors achieve the nice balance of insulation and circulation needed for an efficient icebox. But as early as 1803, an ingenious Maryland farmer, Thomas Moore, had been on the right track. He owned a farm about twenty miles outside the city of Washington, for which the village of Georgetown was the market center. When he used an icebox of his own design to transport his butter to market, he found that customers would pass up the rapidly melting stuff in the tubs of his competitors to pay a premium price for his butter, still fresh and hard in neat, one-pound bricks. One advantage of his icebox, Moore explained, was that farmers would no longer have to travel to market at night in order to keep their produce cool.

Question: The word "rudimentary" in paragraph 2 is closest in meaning to __________.         

Question 24: The author mentions Vivaldi and Tartini in passage as examples of composers whose music___________.    

Of all modern instruments, the violin is apparently one of the simplest. It consist in essence of a hollow, varnished wooden sound box, or resonator, and a long neck covered with a fingerboard, along which four strings are stretched at high tension. The beauty of design, shape, and decoration is no accident, the proportions of the instrument are determined entirely by acoustical considerations. Its simplicity of appearance is deceptive. About 70 parts are involved in the construction of a violin. Its tone and its outstanding range of expressiveness make it an ideal solo instrument. No less important, however, is its role as an orchestral and chamber instrument. In combination with the larger and deeper-sounding members of the same family, the violins form the nucleus of the modem symphony orchestra. The violin has been in existence since about 1550. Its importance as an instrument in its own right dates from the early 1600’s, when it first became standard in Italian opera orchestras. Its stature as an orchestral instrument was raised further when in 1626 Louis XIII of France established at his court the orchestra known as Les vinq-quatre violons du Roy (The King's 24 Violins), which was to become widely famous later in the century. In its early history, the violin had a dull and rather quiet tone resulting from the fact that the strings were thick and were attached to the body of the instrument very loosely. During the eighteenth and nineteenth century exciting technical changes were inspired by such composer-violinists as Vivaldi and Tartini. Their instrumental compositions demanded a fuller, clearer, and more brilliant tone that was produced by using thinner strings and a far higher string tension. Small changes had to be made to the violin's internal structure and to the fingerboard so that they could withstand the extra strain. Accordingly, a higher standard of performance was achieved, in terms of both facility and interpretation. Left-hand technique was considerably elaborated, and new fingering patterns on the fingerboard were developed for very high notes.

Question 23: The word “they” in the passage refers to___________.         

Of all modern instruments, the violin is apparently one of the simplest. It consist in essence of a hollow, varnished wooden sound box, or resonator, and a long neck covered with a fingerboard, along which four strings are stretched at high tension. The beauty of design, shape, and decoration is no accident, the proportions of the instrument are determined entirely by acoustical considerations. Its simplicity of appearance is deceptive. About 70 parts are involved in the construction of a violin. Its tone and its outstanding range of expressiveness make it an ideal solo instrument. No less important, however, is its role as an orchestral and chamber instrument. In combination with the larger and deeper-sounding members of the same family, the violins form the nucleus of the modem symphony orchestra. The violin has been in existence since about 1550. Its importance as an instrument in its own right dates from the early 1600’s, when it first became standard in Italian opera orchestras. Its stature as an orchestral instrument was raised further when in 1626 Louis XIII of France established at his court the orchestra known as Les vinq-quatre violons du Roy (The King's 24 Violins), which was to become widely famous later in the century. In its early history, the violin had a dull and rather quiet tone resulting from the fact that the strings were thick and were attached to the body of the instrument very loosely. During the eighteenth and nineteenth century exciting technical changes were inspired by such composer-violinists as Vivaldi and Tartini. Their instrumental compositions demanded a fuller, clearer, and more brilliant tone that was produced by using thinner strings and a far higher string tension. Small changes had to be made to the violin's internal structure and to the fingerboard so that they could withstand the extra strain. Accordingly, a higher standard of performance was achieved, in terms of both facility and interpretation. Left-hand technique was considerably elaborated, and new fingering patterns on the fingerboard were developed for very high notes.