单选题 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 (轴). That way, the mirrors would always be over the same spot.
The aluminum-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 scientists say that the computer-controlled mirrors could also be made to tilt (倾斜) 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 effects there might be.
单选题 The word "colossal" in Line 3 most likely means ______.
【正确答案】 C
【答案解析】[解析] 释义题。题干意为“第二行中的‘colossal’一词最可能的意思是”。A项意为“核动力的”，B项意为“按轨道运行的”，C项意为“巨大的”，D项意为“旋转的”。根据题干定位至文章第三行，句中thousands of feet across作为后置定语修饰colossal computer-controlled mirrors，由此推断，这些电脑控制的镜子有数千英尺宽，非常庞大。C选项符合题意，故C为正确答案。
单选题 Which of the following is NOT TRUE of the mirrors? ______
【正确答案】 B
【答案解析】[解析] 细节题。题干意为：“对于镜子的描述，以下哪个是不正确的?”该题可根据选项中的关键词运用寻读法定位原文，然后比对选项，运用排除法确定答案。文中第三段第一句提到这些镜子表面涂有铝，并且是塑料的，故A项描述是正确的。第三段第一、二句也提到这些镜子会被折叠放入太空船，太空船进入太空后会将其释放，然后这些镜子就依靠太阳能自行运转。由此推断，这些镜子并不是被直接发射到太空中去的，故B项对镜子的描述是错误的。文中第四段最后一句提到，镜子可以永远对着地球上的同一个地方，故C选项的描述是正确的。文中第三段第一句提到这些镜子反射到地球上的光的范围约长300英里，宽200英里。由此推断，镜子反射到地球上的太阳光的面积非常大，故D选项对镜子的描述是正确的。综上所述，B为正确答案。
单选题 The reflected light should sweep slowly along the surface of the earth because the mirrors ______.
【正确答案】 D
【答案解析】[解析] 细节题。题干意为“被反射的光能缓慢地扫过地球的表面是因为镜子能够”。根据题干中sweep slowly along the surface of the earth定位至第六段第一句，科学家称这些由电脑控制的镜子也能够缓慢地倾斜，这样，被反射的光就能缓慢地扫过地球的表面。D选项(能被调整角度)与其意思一致，故D为正确答案。
单选题 The purpose for slowly tilting the mirrors in space is to ______.
【正确答案】 C
【答案解析】[解析] 细节题。题干意为“在太空中缓慢倾斜镜子的目的是”。根据题干中slowly tilting the mirrors定位至倒数第二段，段中最后两句提到，镜子所反射的太阳光可以帮助这些城市节约电能，并应对诸如停电之类的紧急状况。C选项(节约能源并应对紧急状况)与其意思一致，故C为正确答案。
单选题 According to the last paragraph, the effects of the mirrors on living things are ______.
【正确答案】 B
【答案解析】[解析] 推理题。题干意为“根据最后一段，这些镜子对地球上生命的影响是”。根据题干定位至最后一段。该段提到，目前无人知晓这种人造白昼会给地球上的动植物以及人类带来什么影响，科学家认为这尚待考察。由此推断，这些镜子对地球上生命的影响是未知的，不确定的。B选项(不确定的)符合题意，故B为正确答案。