首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A、When the sun is very active and explosions occur. B、When it is less than 1,500 miles away from the earth. C、When bad weather o
A、When the sun is very active and explosions occur. B、When it is less than 1,500 miles away from the earth. C、When bad weather o
admin
2016-08-29
50
问题
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 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. 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、When the sun is very active and explosions occur.
B、When it is less than 1,500 miles away from the earth.
C、When bad weather occurs more frequently.
D、When there is less forest on the earth.
答案
A
解析
原文提及“太阳的辐射在太阳活跃时或在太阳表面有爆炸发生时尤其危险”。故A正确。
转载请注明原文地址:https://kaotiyun.com/show/6pG7777K
0
大学英语六级
相关试题推荐
Tolearnwithsuccessisnotaverydifficulttaskifsomefundamentalprinciplesarelaidtobeitsbases.Indiscussingthisp
A、Peoplesometimesdosomethingwrongwithgoodintention.B、Oneshoulddiscussitwithothersifhewantstodosomething.C、Th
A、HewaswellknownontheWestCoast.B、HeservedasJamesPolk’sVicePresident.C、Hesupportedfinancialaidtofarmers.D、He
Overacenturyafteritended,theCivilWarremainsthefundamental【B1】_____inAmericanhistory.Itproducedalossoflife【B2】
A、Theyarebothexcellentstudents.B、Theybothhavetotakehistoryandpsychologytests.C、Theyhaven’ttakenfinalexamsbefo
Self-imageisthepictureyouhaveofyourself,thesortofpersonyoubelieveyouare.Includedinyourself-imagearethe【B1】_
A、Beseatedinacomfortablechair.B、Usecomputerswisely.C、Obeytherulesinschool.D、Studywithajoyfulfeeling.C
Businessesarestructuredindifferentwaystomeetdifferentneeds.Thesimplestformofbusinessiscalledan【B1】______pro
A、SurvivalstrategiesforextremeAntarcticcold.B、Whyinactivevolcanoesbecomeactive.C、Theprincipalcausesofglobalwarmi
A、Theuseofoversizedfreightcontainers.B、Safetyproblemswithrailroadtracks.C、Thegrowthoftheautomotiveindustry.D、Th
随机试题
按照价格上升的速度,下列不属于通货膨胀类型的是()。
保险公司要求投保人根据其不同的损失,自负一定的责任,即由被保险人承担的损失额为免赔额。根据规定,保险人向被保险人支付为修复保险标的遭受损失所需的费用时,下列对免赔额的叙述说法正确的一项是( )。
注册验资的临时存款账户在现金管理方面只收不付。()
请看下面的教学片段,再回答相应问题.在教学“加法——三位数加两、三位数的进位加法”一课中师:小明做了三道加法的竖式计算,同学们帮他查一查有没有错误.出示在黑板上:师:先仔细地观察一下有没有错误,然后把你发现的问题和
下列犯罪分子中,应当认定为主犯的是()(2012年法学基础课单选第9题)
(2010年上半年)在编制项目管理计划时,项目经理应遵循编制原则和要求,使项目计划符合项目实际管理的需要。以下关于项目管理计划的叙述中,(32)是不正确的。
采用直通交换模式的交换机开始转发数据帧时已经接收到的帧长度是()。
运算符重载时不需要保持的性质是()。
A.selflessB.builtC.complexD.butE.executeF.sustainedG.cheatedH.issuesI.advantagesJ.scholarlyK.tighte
A、Theycanshareitwithothers.B、Theycanbuythingstheywant.C、Theycansaveit.D、All-abovementioned.D
最新回复
(
0
)