20.The oddness of life in space never quite goes away.Here are some examples.
First consider something as simple as sleep.Its position presents its own challenges.The main question is whether you want your arms inside or outside the sleeping bag.If you leave your arms out,they float free in zero gravity,often giving a sleeping astronaut the look of a funny balled (芭蕾)dancer."I'm an inside guy,"Mike Hopkins says,who returned from a six-month tour on the International Space Station."I like to be wrapped up."
On the station,the ordinary becomes strange.The exercise bike for the American astronauts has no handlebars.It also has no seat.With no gravity,it's just as easy to pedal violently.You can watch a movie while you pedal by floating a microcomputer anywhere you want.But station residents have to be careful about staying in one place too long.Without gravity to help circulate air,the carbon dioxide you exhale (呼氣) has a tendency to form an invisible (隱形的)cloud around you head.You can end up with what astronauts call a carbon-dioxide headache.
Leroy Chiao,54,an American retired astronaut after four flights,describes what happens even before you float out of your seat,"Your inner ear thinks you're falling.Meanwhile your eyes are telling you you're standing straight.That can be annoying-that's why some people feel sick."Within a couple days-truly terrible days for some-astronauts'brains learn to ignore the panicky signals from the inner ear,and space sickness disappears.
Space travel can be so delightful but at the same time invisibly dangerous.For instance,astronauts lose bone mass.That's why exercise is considered so vital that National Aeronautics and Space Administration (NASA) puts it right on the workday schedule.The focus on fitness is as much about science and the future as it is about keeping any individual astronauts return home,and,more importantly,how to maintain strength and fitness for the two and a half years or more that it would take to make a round-trip to Mars.
26.What is the major challenge to astronauts when they sleep in space?C
A.Seeking a way to fall asleep quickly
B.Choosing a comfortable sleeping bag
C.Deciding on a proper sleep position
D.Finding a right time to go to sleep.
27.The astronauts will suffer from a carbon-dioxide headache whenD.
A.the y circle around on their bikes
B.they use microcomputers without a stop
C.they watch a movie while pedaling
D.they exercise in one place for a long time
28.Some astronauts feel sick on the station during the first few days becauseB.
A.their senses stop working
B.their brains receive contradictory (矛盾的)messages
C.they float out of their seats unexpectedly
D.They have to stand up straight
29.One of the NASA's major concerns about astronauts isB.
A.how much exercise they do on the station
B.how they can remain healthy for long in space
C.whether they can recover after returning home
D.whether they are able to go back to the station.
分析 這是一篇說明文.本文通過舉例說明了太空生活的奇妙:在太空睡覺時,對宇航員來說主要的挑戰(zhàn)在于恰當(dāng)?shù)乃咦藙荩挥詈絾T在一個地方運動久了會出現(xiàn)碳毒性頭痛;宇航員的大腦接收到矛盾的信息時會感到惡心.最后告訴我們美國國家宇航局對宇航員主要的擔(dān)心是宇航員回家后的修養(yǎng)期和如何在太空長久地保持健康.
解答 26.C.細(xì)節(jié)理解題.根據(jù)第二段第一、二句"First consider something as simple as sleep.Its position presents its own challenges."可知在太空睡覺時,對宇航員來說主要的挑戰(zhàn)在于恰當(dāng)?shù)乃咦藙荩蔬xC.
27.D.細(xì)節(jié)理解題.根據(jù)第三段中"But station residents have to be careful about staying in one place too long.…You can end up with what astronauts call a carbon-dioxide headache"可知宇航員在一個地方運動久了會出現(xiàn)碳毒性頭痛.故選D.
28.B.細(xì)節(jié)理解題.根據(jù)第四段中"Your inner ear thinks you're failing.Meanwhile your eyes are telling you you're standing straight.That can be annoying-that's why some people feel sick."可知宇航員在大腦接收到矛盾的信息時會感到惡心.故選B.
29.B.細(xì)節(jié)理解題.根據(jù)最后一段倒數(shù)第一、二句"The focus on fitness is as much about science and the future as is about keeping any individual astronaut healthy…NASA is worried about two things:…and,more importantly,how maintain strength and fitness…"可知美國國家宇航局對宇航員主要的擔(dān)心之一是如何在太空長久地保持健康.故選B.
點評 本文是一篇科教類閱讀,題目涉及多道細(xì)節(jié)理解題.做題時學(xué)生應(yīng)仔細(xì)閱讀原文,把握文章主要內(nèi)容,聯(lián)系文章上下文內(nèi)容并結(jié)合所給選項含義,從中選出正確答案,一定要做到有理有據(jù),切忌胡亂猜測.