Another thing an astronaut has to learn about is eatingin space. Food is wei

游客2025-03-06 33

问题 Another thing an astronaut has to learn about is eatingin space. Food is weightless, just as men are.
Food for space has to be packed in special ways. Some of it goes into tubes that a man can squeeze into his mouth. Bite-sized cookies are packed in plastic.
There is a good reason for covering each bite, The plastic keeps pieces of food from traveling in the spaceship. On the earth very small pieces of food would simply fall to the floor. But gravity doesn’t pull them to the floor when they are out of the plastic in a spaceship. They move here and there and can get into a man’s eyes or into the spaceship’s instruments. If any of the instruments is blocked, the astronauts may have trouble getting safely home.
As astronauts travel on longer space trips, he must take time to sleep. An astronaut can fit himself to his seat with a kind of seat belt. Or, if he wants to, he can sleep in a sleeping bag which is fixed in place under his seat. But be careful he must put his hands under the belt when he goes to sleep. This is because he is really afraid that he might touch one of controls that isn’t supposed to be touched until later. [br] In a spaceship, astronauts can( ).

选项 A、walk just as they do on the earth
B、not eat anything because it’s dangerous
C、control the spaceship when they are sleeping
D、not litter small things or it will make trouble

答案 D

解析推理判断题。可以用排除法。在宇宙中，由于失重，宇航员不可能像在地球上一样行走，所以A不对。因为食物也像宇航员一样失重，吃东西就会变得非常困难，而不存在危险，所以B也不对。为了防止在睡眠中不小心触摸控制键，宇航员要将双手放在安全带下，因此他睡着的时候是不能控制宇宙飞船的，这样C也排除了。为了防止小东西由于失重飞到人眼睛里或机械中，宇航员是不能到处乱扔东西的，所以只有D是正确的。

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