首页
登录
职称英语
What forms of radiation are feared by astronauts? [originaltext] Not long ag
What forms of radiation are feared by astronauts? [originaltext] Not long ag
游客
2023-11-13
63
管理
问题
What forms of radiation are feared by astronauts?
Not long ago it was assumed that the dangers man would meet in Space would be terrible, the main ones being radiation and the danger of being hit
by meteors. It is perhaps worth remembering that less than two centuries ago the dangers of train travel seemed similarly terrible. A man would certainly die, it was thought, if carried along at a speed of thirty kilometers per hour.
There are two sorts of radiation man must fear in space. The first is radiation from the sun, and this is particularly dangerous when the sun is very ac five and explosions are occurring on its surface. The second, less harmful form comes from the so-called Van Allen Belts. These are two areas of radiation about 1 ,500 miles away from the earth. Neither of these forms of radiation area is dangerous to us on the earth, since we are protected by our atmosphere. Specifically, it is that part of our atmosphere known as the ozonosphere which protects us. This is a belt of the chemical ozone between 12 and 21 miles from the ground, which absorbs all the radiation.
Once outside the atmosphere, however, man is no longer protected, and radiation can be harmful in a number of ways. A distinction must be drawn between the short- and long-term effects of radiation. The former are merely unpleasant, but just because an astronaut returning from a journey in space does not seem to have been greatly harmed, we cannot assume that he is safe. The long-term effects can be extremely serious, even leading to death.
选项
A、Radiation from the sun.
B、Radiation from the Van Allen Belts.
C、Radiation from the meteors.
D、Both A and B
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3184556.html
相关试题推荐
FoodwasteinSeattleisfinallymadeintoakindof[br][originaltext](11
Themanstopstotakehisdogoutsidetodoexercisebecause[br][originaltext
Themanstopstotakehisdogoutsidetodoexercisebecause[br][originaltext
Themanstopstotakehisdogoutsidetodoexercisebecause[originaltext]M:Th
WhatdoestheMinisterwanttokeepaneyeon?[br][originaltext]RussianE
WhatdoestheMinisterwanttokeepaneyeon?[originaltext]RussianEmergen
Whatisthefocusofthenews?[br][originaltext]FINAsaidGreekgovernmen
Whatisthefocusofthenews?[originaltext]FINAsaidGreekgovernmentoffi
Whichfonmswasthebasisforphotography?[br][originaltext]Thecamerais
Whichfonmswasthebasisforphotography?[originaltext]Thecameraisoften
随机试题
AManWhoHadNoEyesAbeggarwascomingdowntheave
Televisionisnowplayingaveryimportantpartinourlife.Buttelevision,
教师既可成为我国教育法制监督的主体也可成为我国教育法制监督的客体。()
对偶极子极化描述正确的是,该极化特点是()。A.所需时间短 B.在频
患者男,68岁。患心脏瓣膜病、房颤20年,服用地高辛5年。近3天突然出现恶心、2
在小组活动中,社会工作者想要塑造信任的小组气氛,需要从()方面入手。A.主动与督
追踪性评估常用的方法包括()。 (A)会谈法(B)测验法 (C)观察法
(2017年真题)下列药物使用方式,正确的是( )A.酵母片在餐后整片用水送服
以采取邀请招标的情形有( )。A.工期较长的 B.技术复杂,只有少量潜在投标人
根据医疗废物管理条例,医疗废物集中贮存、处置装罝设施的设置地点应( )A.远离
最新回复
(
0
)