单选题
Another thing an astronaut has to learn about is eating in 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.
单选题
Why would astronauts cover each bite of food in space?
【正确答案】
B
【答案解析】[解析] 第二段第五句：“They move here and there and can get into a man"s eyes or into the spaceship"s instruments. ”
事实细节题。根据定位句可知，在太空中由于不存在重力，食物会到处移动，可能飞到人的眼睛里或宇宙飞船的仪器中从而引起麻烦。故选B。
单选题
In a spaceship, astronauts can ______.
【正确答案】
D
【答案解析】[解析] 全文。
推理判断题。本题可以用排除法。根据第一段最后一句“Food is weightless, just as men are. ”可知，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，但不存在危险，所以B不对。根据最后一段最后两句“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. ”可知，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，所以C不对。为了防止小东西由于失重飞到人的眼睛里或机械中，宇航员是不能到处乱扔东西的。故选D。
单选题
In what way is food for space packed?
【正确答案】
D
【答案解析】[解析] 第一段最后两句：“Some of it goes into tubes that a man can squeeze into his mouth. Bite-sized cookies are packed in plastic. ”
事实细节题。根据定位句可知，有些食物是被放在管子里以方便挤入口中，小饼干则用塑料袋包装起来，以防它们乱漂。故选D。
单选题
Why does an astronaut put his hand under his belt when he sleeps?
【正确答案】
B
【答案解析】[解析] 第三段最后一句：“This is because he is really afraid that he might touch one of controls that isn"t supposed to be touched until later. ”
事实细节题。根据定位句可知，为了防止在睡觉时自己的手在无意中碰到各种不该碰的开关，宇航员要将双手放在安全带下。故选B。