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. The pilot of the plane was Captain Thomas Nash. Looking eastward, Nash saw twelve orange lights in a row, moving at an extremely high speed. As an experienced flyer, he had never seen anything like them. Thinking that they might be a new German weapon, he decided to follow them. But when he swung the plane around and headed directly for the lights, they disappeared.

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 the earth. They feed in part on the air and partly on energy from sunlight. Being almost pure energy themselves, they can give light at night. During the day they become invisible.

Before World WarⅡ, continues the theory, there was little radiated (辐射) energy available on the earth’s surface. Then came the development of rockets, atomic reactor (核反应堆), and hydroelectric (水力发电的) plants. The space creatures are attracted by these sources of energy. At night when no energy is sent from sunlight, they go down into the lower levels to search a meal. They may even come into the scope of human eyesight. This explains the fact that they have been sighted now and then from the earth since 1942.

54．Which of the following best states the main idea of the passage?

A．The secret of nature can be completely explained.

B．Captain Nash may have been the first to see the lights in space.

C．Captain Nash saw twelve orange lights moving at a high speed.

D．According to an interesting theory, the orange lights are space animals.

55．The strange orange lights were first seen         .

A．from the ground                                  B．from a rocket ship

C．during World War I                             D．during World WarⅡ

56．The theory says that during the daytime the space animals        .

A．can’t be seen                                       B．shine brightly in the sky

C．can be seen from the earth                    D．visit the earth’s surface

57．If the space theory is true, the creatures go down to the lower places in order to         .

A．make connection with man                   B．search for man – made energy

C．attract curiosity                                   D．escape detection