IV. Fill one suitable word in each numbered space to finish the passage.
THE GREEN REVOLUTION
In the Green Revolution, scientists collected thousands of genetic varieties of rice and wheat from all over the world, and cross-bred them (26) ........ they found varieties that produced high yields and were resistant to diseases. Bút these hybrid strains (27) ......... from four to seven times as much water per hectare and this is a limiting factor in some areas. Moreover, to (28) ........ high yields, the new varieties need much more fertilizers per hectare than the (29) ........ varieties did. Unfortunately, many developing countries have been experiencing fertilizer shortages (30) ....... the price of oil began to rise in the early 1970s. Scientists are also aware (31) ........ the danger of relying on only a few strains of rice and wheat. They remember the Irish famine (32) ........ 1845 and 1850, when potato blight wiped (33)........the single crop that fed almost all the (34) .......... One million people died. Scientists are therefore (35) ......... and maintaining varieties of food crops from all over the world.
V. Read the following passage and choose the correct answer A, B, c, or D toeach of the questions.
By the 1820's in the United States, when steamboats were common on western waters, these boats were mostly powered by engines built in the West (Pittsburgh, Cincinnati or Louisville), and of a distinctive western design specially suited to western needs. The first steam engines in practical use in England and the United States were of low-pressure design. This was the type first developed by James Watt, then manufactured by the firm of Boulton and Watt, steam was accumulated in a large, double-acting vertical cylinder, but the steam reached only a few pounds of pressure per square inch. It was low-pressure engines of this type that were first introduced into the United States by Robert Fulton. He imported such a Boulton and Watt engine from England to run the Clemont. But this type of engine was expensive and complicated, requiring many precision-fitted moving parts.
The engine that became standard on western steamboats was of a different and novel design. It was the work primarily of an unsung hero of American industrial progress Oliver Evans (1755 - 1819). The self-educated son of a Delaware farmer, Evans early became obsessed by the possibilities of mechanized production and steam power. As early as 1802 he was using a stationary steam engine of high - pressure design in his mill. Engines of this type were not unknown, but before Evans they were generally considered impractical and dangerous.
Within a decade the high-pressure engine, the new type had become standard on western waters. Critics ignorant of western conditions often attacked it as wasteful anddangerous. But people who really knew the Ohio, the Missouri and the Mississippi insisted with good reasons that it was the only engine for them. In shallow western rivers the weight of vessel and engine was important, a heavy engine added to the problem of navigation. The high-pressure engine was far lighter in proportion to horsepower, and with less than half as many moving parts was much easier and cheaper to repair. The main advantages of low-pressure engines were safe operation and economy of fuel consumption, neither of which meant much in the West.
36. What is the passage mainly about?
A. Steamboat engines in the western United States
B. River travel in the western United States
C. A famous United States inventor
D. The world's first practical steamboat
37. What might be the Clermont in the first paragraph?
A. A river B. A factory C. A boat D. An engine
38. Who developed the kind of steam engine used on western steamboats?
A. Watt B. Boulton C. Fulton D. Evans
39. The word "novel" in the second paragraph is closest in meaning to ______.
A. fictional B. intricate C. innovative D. powerful
40. What opinion of Evans is suggested by the use of the term "unsung hero" in thesecond paragraph?
A. More people should recognize the importance of his work.
B. More of his inventions should be used today.
C. He should be credited with inventing the steam engine.
D. More should be learned about his early life.
41. What does the author imply about Evans?
A. He went to England to learn about steam power.
B. He worked for Fulton.
C. He traveled extensively in the West.
D. He taught himself about steam engines.
42. What does the author imply about the western rivers?
A. It was difficult to find fuel near them.
B. They flooded frequently.
C. They were difficult to navigate.
D. They were rarely used for transportation.
43. The word "it" in the third paragraph refers to______
A. decade B. high-pressure C. weight D. problem
44. The word "vessel" in the third paragraph is closest in meaning to ______.
A. fuel B. crew C. cargo D. craft
15. Which of the following points was made by the critics of high-pressure engines?
A. They are expensive to import. B. They arế not powerful enough,
C. They are dangerous. D. They weigh too much.
IV. Fill one suitable word in each numbered space to finish the passage.
THE GREEN REVOLUTION
In the Green Revolution, scientists collected thousands of genetic varieties of rice and wheat from all over the world, and cross-bred them (26) ....till.... they found varieties that produced high yields and were resistant to diseases. Bút these hybrid strains (27) .....needed.... from four to seven times as much water per hectare and this is a limiting factor in some areas. Moreover, to (28) ....achieve.... high yields, the new varieties need much more fertilizers per hectare than the (29) ....previous.... varieties did. Unfortunately, many developing countries have been experiencing fertilizer shortages (30) ....since.. the price of oil began to rise in the early 1970s. Scientists are also aware (31) ....of.... the danger of relying on only a few strains of rice and wheat. They remember the Irish famine (32) ....between.... 1845 and 1850, when potato blight wiped (33) ....out.... the single crop that fed almost all the (34) .....population..... One million people died. Scientists are therefore (35) .....collecting.... and maintaining varieties of food crops from all over the world.
V. Read the following passage and choose the correct answer A, B, c, or D toeach of the questions.
By the 1820's in the United States, when steamboats were common on western waters, these boats were mostly powered by engines built in the West (Pittsburgh, Cincinnati or Louisville), and of a distinctive western design specially suited to western needs. The first steam engines in practical use in England and the United States were of low-pressure design. This was the type first developed by James Watt, then manufactured by the firm of Boulton and Watt, steam was accumulated in a large, double-acting vertical cylinder, but the steam reached only a few pounds of pressure per square inch. It was low-pressure engines of this type that were first introduced into the United States by Robert Fulton. He imported such a Boulton and Watt engine from England to run the Clemont. But this type of engine was expensive and complicated, requiring many precision-fitted moving parts.
The engine that became standard on western steamboats was of a different and novel design. It was the work primarily of an unsung hero of American industrial progress Oliver Evans (1755 - 1819). The self-educated son of a Delaware farmer, Evans early became obsessed by the possibilities of mechanized production and steam power. As early as 1802 he was using a stationary steam engine of high - pressure design in his mill. Engines of this type were not unknown, but before Evans they were generally considered impractical and dangerous.
Within a decade the high-pressure engine, the new type had become standard on western waters. Critics ignorant of western conditions often attacked it as wasteful anddangerous. But people who really knew the Ohio, the Missouri and the Mississippi insisted with good reasons that it was the only engine for them. In shallow western rivers the weight of vessel and engine was important, a heavy engine added to the problem of navigation. The high-pressure engine was far lighter in proportion to horsepower, and with less than half as many moving parts was much easier and cheaper to repair. The main advantages of low-pressure engines were safe operation and economy of fuel consumption, neither of which meant much in the West.
36. What is the passage mainly about?
A. Steamboat engines in the western United States
B. River travel in the western United States
C. A famous United States inventor
D. The world's first practical steamboat
37. What might be the Clermont in the first paragraph?
A. A river B. A factory C. A boat D. An engine
38. Who developed the kind of steam engine used on western steamboats?
A. Watt B. Boulton C. Fulton D. Evans
39. The word "novel" in the second paragraph is closest in meaning to ______.
A. fictional B. intricate C. innovative D. powerful
40. What opinion of Evans is suggested by the use of the term "unsung hero" in thesecond paragraph?
A. More people should recognize the importance of his work.
B. More of his inventions should be used today.
C. He should be credited with inventing the steam engine.
D. More should be learned about his early life.
41. What does the author imply about Evans?
A. He went to England to learn about steam power.
B. He worked for Fulton.
C. He traveled extensively in the West.
D. He taught himself about steam engines.
42. What does the author imply about the western rivers?
A. It was difficult to find fuel near them.
B. They flooded frequently.
C. They were difficult to navigate.
D. They were rarely used for transportation.
43. The word "it" in the third paragraph refers to______
A. decade B. high-pressure C. weight D. problem
44. The word "vessel" in the third paragraph is closest in meaning to ______.
A. fuel B. crew C. cargo D. craft
15. Which of the following points was made by the critics of high-pressure engines?
A. They are expensive to import. B. They arế not powerful enough,
C. They are dangerous. D. They weigh too much.
