首页
登录
职称英语
[originaltext] [9]Not long ago it was assumed that the dangers man would mee
[originaltext] [9]Not long ago it was assumed that the dangers man would mee
游客
2023-08-15
14
管理
问题
[9]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. [10]The first is radiation from the sun, and this is particularly dangerous when the sun is very active 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. [11]Neither of these forms of radiation is a danger 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.
9. What was one of the main dangers man would meet in space?
10. When is the sun radiation particularly dangerous to human beings?
11. Why did the speaker say neither of these forms of radiation is a danger to us?
选项
A、Traffic accidents.
B、Radiation.
C、Train travel.
D、Air crash.
答案
B
解析
原文提及“不久前人们认为在太空中会遭遇到严重的威胁,主要有辐射和流星撞击”,故B正确。
转载请注明原文地址:https://tihaiku.com/zcyy/2929153.html
相关试题推荐
[originaltext]TodayI’dliketotalkaboutthesculptorHenryMoore,inpa
[originaltext]TodayI’dliketotalkaboutthesculptorHenryMoore,inpa
[originaltext]TodayI’dliketotalkaboutthesculptorHenryMoore,inpa
[originaltext]Let’sbegintodaybydiscussingenzymes.Enzymesarewhatma
[originaltext]Let’sbegintodaybydiscussingenzymes.Enzymesarewhatma
[originaltext]Inthe18thcenturyFrencheconomistsprotestedtheexcessive
[originaltext]Inthe18thcenturyFrencheconomistsprotestedtheexcessive
[originaltext]TheeconomiccrisisinEuropeandNorthAmericaledtomoret
[originaltext]M:Goodmorning.Doctor.W:Goodmorning,Mr.White.WhatcanId
[originaltext]M:Goodmorning.Doctor.W:Goodmorning,Mr.White.WhatcanId
随机试题
MaintainingFriendshipinAdolescenceSecondaryschoolc
D
A.室间隔缺损 B.房间隔缺损 C.动脉导管未闭 D.肺动脉瓣狭窄 E.
患者,女,30岁。近2个月中度发热,全身肌痛,四肢关节肿痛,口腔溃疡。尿常规显示
2016年6月份,我国社会消费品零售总额26857亿元,同比增长10.6%,环比
患者女,32岁。便溏腹痛,泻而不爽,大便黄褐而臭,肛门灼热,渴欲饮,小便黄赤,舌
教育教学工作应当符合教育规律和(),面向全体学生,教书育人,将德育、智育、体育、
下列哪一项属于金融衍生品市场的功能?(??)A.降低风险功能 B.控制价格功能
期货公司及其从业人员从事期货投资咨询业务,不予许的行为有()。A.向客户做获利
患者男,缺失,余留牙正常,口底距舌侧龈缘的距离为4mm。如果设计铸造支架可摘局部
最新回复
(
0
)