单选题
We don"t have beds in the spacecraft, but we do have sleeping bags. During the day, when we are working, we leave the bags tied to the wall, out of the way. At bedtime we untie them and take them wherever we"ve chosen to sleep.
On most spacecraft flights everyone sleeps at the same time. No one has to stay awake to watch over the spacecraft; the craft"s computers call us on the radio.
On the spacecraft, sleep-time doesn"t mean nighttime. During each ninety-minute orbit (轨道) the sun "rises" and shines through our windows for about fifty minutes, then it "sets" as the spacecraft takes us around the dark side of the Earth. To keep the sun out of our eyes, we wear black sleep masks.
It is surprisingly easy to get comfortable and fall asleep in space. Every astronaut (宇航员) sleeps differently : some sleep upside down, some sideways, and some right side up. When it"s time to sleep, I take my bag, my sleep mask and my tape player with earphones and float (漂浮) up to the flight deck (驾驶舱). Then I get into the bag, and float in a sitting position just above a seat, right next to a window. Before I pull the mask down over my eyes, I relax for a while, listening to music and watching the Earth go by under me.
单选题
When the astronauts are working, sleeping bags are fastened ______.
【正确答案】
A
【答案解析】[解析] 事实细节题。该题题干的意思是“宇航员们工作的时候，睡袋被系在______”。根据文章第一段的第二句：“During the day, when we are working, we leave the bags tied to the wall, out of the way.”可以很容易得出结论：白天“我们”工作的时候，会把睡袋拴在墙上，不让它们挡道。因此，该题答案为A。
单选题
Why can all the astronauts sleep at the same time?
【正确答案】
D
【答案解析】[解析] 事实细节题。该题问“为什么所有的宇航员可以在同一时间睡觉?”根据文章第二段：“...everyone sleeps at the same time. No one has to stay awake to watch over the spacecraft; the craft"s computers call us on the radio.”可知：因为飞船上有计算机监测飞船运行，所以不需要人为监测飞船的飞行情况。因此，该题的正确答案为D。
单选题
To relax himself before sleep, the writer often ______.
【正确答案】
C
【答案解析】[解析] 事实细节题。该题问“为了在睡前放松，作者通常______”。通过文章最后一段的最后一句话：“Before I pull the mask down over my eyes, I relax for a while, listening to music and watching the Earth go by under me.”可知：作者在睡前会听一会儿音乐来放松自己。因此，正确答案为C。
单选题
How long does it take the spacecraft to go round the Earth?
【正确答案】
C
【答案解析】[解析] 推理判断题。该题问“飞船环绕地球一周需要多长时间?”通过文章第三段的第二句话：“During each ninety-minute orbit the sun "rises" and shines through our windows for about fifty minutes, then it "sets" as the spacecraft takes us around the dark side of the Earth.”可知：飞船绕地球飞行一周的轨道时长为90分钟。因此，该题的正确答案为C。