The aluminium-coated (涂铝的), plastic mirrors could be folded up and packed into a spaceship, according to the scientists. Once released a few hundred miles in space, the mirrors, powered by a solar-powered engine, could mark the rest of the trip into space on their own.
The seientists say that the computer-controlled mirrors could also be made to tilt (倾斜) slowly, so the refected sunlight would sweep slowly along the surface of the earth. For example, as night fell, the mirrors could be tilted to light up Boston. Later on, as darkness spread slowly westward. Chicago, for example, then San Francisco could be lit up. The reflected sunlight would allow these cities to save up electricity. And in emergencies, such as power-failures, the mirrors could light up the affected area.
What no one knows yet is what effect this artificial daytime would have on plants, animals, and humans. Would it confuse some animals and harm plants that are used to regular day-night cycles? The scientists recommond that studies be done to find out what had effects there might be.
26. The word "colossal" in Line 3 most likely means ______.
A) nuclear-powered .
B) orbiting
C) giant
D) spinning
27. Which of the following is NOT TRUE of the mirrors?
A) They would be made of plastic and coated with aluminium.
B) They could be launched directly into space.
C) They would stay in the same position over the earth.
D) They could reflect sunlight to a large area on the earth.
28. The reflected light sould sweep slowly along the surface of the earth because the mirrors ______.
A) would be operated by solar-powered engines
B) would orbit thousands of miles high to catch the sun's light
C) could move around the earth at the same speed as the earth turns on its axis
D) could be made to adjust their angles
29. The purpose for turning night into day is to ______.
A) confuse animals and plants
B) light up more cities
C) save energy and deal with emergencies
D) enable people to work longer hours
30. The writer of this passage ______.
A) gives an objective account of the mirrors
B) seems to be much worried about the effect of the mirrors
C) is in favour of the wide use of the mirrors
D) suggests that artificial daylight is harmful to living being
Passage Three
Questions 31 to 35 are based on the following passage:
As supplier of most of the food we eat and of raw materials for many industrial processes, agriculture is clearly an important area of the economy. But the industrial performance of agriculture is even more important than this. For in nations where the productivity of farmers is low, most of the working population is needed to raise food and few people are available for production of investment goods or for other activities required for economic growth. Indeed, one of the factors related most closely to the per capital income (人均收入) of a nation is the fraction of its population engaged in farming. In the poorest nations of the world more than half of the pupolation lives on farms. This compares sharply with less than 10 per cent in western Europe and less than 4 per cent in the United States.
In short, the course of economie development in general depends in a fundamental way on the performance of farmers. This performance of farmars. This performance in turn, depends on how agriculture is organized and on the economie environment, or market structure, within which it function. In the following pages the performance of American agriculture is examined. It is approgrlate to begin with a conversation of its market structure.
31. This passage is most probably ______.
A) a news item
B) part of an introduction of a book
C) part of a lecture
D) an advertisement
32. What is most improtant to agriculture is ______.
A) the amount of food it produces
B) the per capital income of farmers
C) its industrial performance
D) the production of investment goods
33. The word "this" in Line 4 refers to ______.
A) the provision of food and raw materials
B) the productivity of farmers
C) the production of investment goods
D) the economy as a whole
34. The performance of farmers essentially determines ______.
A) the size of the working population
B) the organization of agriculture
C) the market atructure
D) the general development of economy
35. This passage will most probably be followed by a discussion of ______.
A) the stucture of American farming population
B) the market structure of American agriculture
C
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