单选题 On the night of May 7, 1942, a plane took off from an Air Force base in England to stop German fighters over the English Channel. Pilot of the plane was Captain Thomas Nash. Looking eastward, Nash saw twelve orange lights in a row, moving at a fantastic rate of speed. As a sophisticated flyer, he had never seen anything like them. Thinking that they might be a new German weapon, he decided to chase them. But when he Swung the plane around and headed directly for the lights, they vanished.
Captain Nash may have been the first to see such orange lights but he wasn't the last. His experience was repeated several times by pilots during World War Ⅱ in Europe and the Far East. What were they?
No one knows for sure, but there is an interesting theory to explain them. According to this theory, the orange lights are space animals--animals specially adapted to life in the upper atmosphere just as some creatures are adapted to life at the bottom of the sea. These space animals, the theory says, live so far up in the atmosphere that they are invisible from earth. They feed in part on the water in air and partly on energy from sunlight. Being almost pure energy themselves, they can adjust their bodies to glow at night. During the day they become invisible.
Before World War Ⅱ, continues the theory, there was little radiated energy available on the earth's surface. Then there came the development of rockets, atomic reactors, and hydroelectric plants. The space creatures are attracted by these sources of energy. At night when no energy emitted from sunlight, they go down into the lower levels to search a meal. They may even drift into the scope of human eyesight. This explains the fact that they have been sighted periodically from the earth since 1942.

单选题 The best statement of the main idea of this passage if that ______.
【正确答案】 C
【答案解析】[解析] 全文大意为“在二战中飞行员看到一种桔黄色光线但其又很快消失,同时又有一种理论来解释这种现象”。选项A只是表面现象,选项B、D均不正确。
单选题 The strange orange lights were first seen ______.
【正确答案】 D
【答案解析】[解析] 由文章第二段可以看出“Captain Nash may have been the first to see such orange lights”。
单选题 The theory says that during the daytime the space animals ______.
【正确答案】 B
【答案解析】[解析] 由第三段最后一句话“During the day they become invisible.”得知。
单选题 If the space animal theory is true, the creatures go down to the lower regions in order to ______.
【正确答案】 C
【答案解析】[解析] 最后一段中“At night when no energy emitted from sunlight,they go down into the lower levels to search a meal.”推知。
单选题 The space animal theory would seem to indicate that ______.
【正确答案】 A
【答案解析】[解析] 此题可以先排除错误选项,B、C、D项与文章大意无关。