Computers may one day turn night into day—with good old, natural sunlight. Colossal computer-controlled mirrors, thousands o

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问题     Computers may one day turn night into day—with good old, natural sunlight.
    Colossal computer-controlled mirrors, thousands of feet across, may one day orbit the earth, reflecting sunlight onto a darkened United States.
    Some scientists say that 16 of these mirrors, each about a half mile across, could aim their reflected light at one area on the earth that was about 200 miles by 300 miles. That much light would equal about 56 moons.
    The mirrors would be so high that they could catch the sun’s light as it was shining on the other side of the earth. The mirrors could orbit—thousands of miles high—at the same speed as the earth turns on its axis. That way, the mirrors would always be over the same spot. The aluminium-coated, 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 make the rest of the trip into space on their own.
    The scientists say that the computer-controlled mirrors could also be made to tilt slowly so the reflected 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 recommend that studies be done to find out what bad effects there might be.
Which of the following is NOT true of the mirrors?

选项 A、They would be made of plastic and coated with aluminium.
B、They could reflect sunlight to a large area on the earth.
C、They would stay in the same position over the earth.
D、They could be launched directly into space.

答案D

解析 本题是一道判断是非题。问关于这个巨型反射镜下面哪个说法是不正确的。文章指出,有些科学家说,每个镜面的直径约半英里的共16个这种镜面能将反射光线对准地球上某个200×300英里见方的区域,这种光的强度大约相当于56个月亮。镜面高悬空中的高度足以使它们接收到射向地球另一面的太阳光线。反射镜可在数千英里的高空以地球绕地轴运行的同样速度做轨道运行。这样一来,镜面就会总在同一地点的上空。据科学家们说这样的塑料镀铝镜面可以折叠起来,装入宇宙飞船。一经在几百英里高的空中释放,这些镜面便会被太阳能发动机驱动,自己走完其余的太空旅程。因此,本题的正确答案应是D“文章中没有提到这种反射镜可以被直接发射进入太空”。
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