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
2023-02-20
41
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。事实细节题。原文提到一个叫Van Allen Belts的辐射区域,它们距离地球不到1500英里,这跟太阳的辐射没有关系,B错误;C和D未提及。
转载请注明原文地址:https://kaotiyun.com/show/mrvD777K
0
大学英语六级
相关试题推荐
Veryoldpeopledoraisemoralproblemforalmosteveryonewhocomesintotouchwiththem.Theirvalues—thiscan’tberepeatedt
Computertechnologyisadvancingsofastthatoldhardwarequicklybecomescompletelyobsolete.Theelectronicwaste(e-waste)f
Computertechnologyisadvancingsofastthatoldhardwarequicklybecomescompletelyobsolete.Theelectronicwaste(e-waste)f
Whilepeoplecomplainabouttheirhecticlivesanddemandingschedules,onemightbejustifiedinsuspectingthattheyarebeing
Neithertheprincipalortheteachershadbeensatisfiedwiththeadditionofacrossingguard.Theywantedatrafficlightinst
Bothplayersappearfasterandmore________andareeagertoseewhatopportunitiesarisefrombeinglighter.
学问要有根底,根底要打得平正坚实,以后永远受用。初学阶段的科目之最重要的莫过于语文与数学。语文是阅读达意的工具,国文不通便很难表达自己,外国文不通便很难吸取外来的新知。数学是思想条理之最好的训练。其他科目也各有各的用处,其重要性很难强分轩轾,例如体育,从一
沙漠里真有魔鬼吗?在那时人们的知识水平看起来,确像是有魔鬼在作怪。但是人们掌握了自然规律以后便可把这种光怪陆离的现象说清楚。这种现象在大戈壁夏天中午是常见的。当人们旅行得渴不可耐的时候忽然看见一个很大的湖。里面蓄着碧蓝的清水,看来并不很远。当人们欢天喜地向
B细节辨认题。当男士问女士希望看到什么样的措施时,女士说应该出台一个关于道路照明的标准,以有效避免光线外溢。因此本题答案为B。
Whenyoutakemedicine,becarefulnotto________thatamountprintedonthebottle,foroverdosemayharmyourhealth.
随机试题
初产妇,从分娩后第2天起,持续3天体温在37.5℃左右,子宫收缩好,无压痛,会阴伤口无肿胀及压痛,恶露淡红色,无臭味,双乳肿胀且有硬结。发热的原因最可能是
女性,23岁,夜间排尿后突然右下腹剧痛,随后出现恶心、呕吐,平时月经规律,末次月经为10天前。妇科检查:子宫右侧可触及拳头大小囊实性包块,触痛,推移后疼痛加剧,首先考虑
如果某项目产品销售价格从1000元上升到1100元,财务净现值从2000万元增加到2560万元,则产品销售价格的敏感度系数应为()。
当工程网络计划的计算工期不等于计划工期时,正确的结论是( )。
下列各项中,表述正确的是( )。
(2016年真题)遗传素质具有可塑性。
将某植物花冠切成大小和形状相同的细条,分为a,b,c,d,e和f组(每组的细条数相等),取上述6组细条分别置于不同浓度的蔗糖溶液中,浸泡相同时间后测量各组花冠细条的长度,结果如图所示。假如蔗糖溶液与花冠细胞之间只有水分交换,则()。
领导让你调查农民工子女入学问题,你怎么办?
福州大洋百货为了庆祝春节,特举行让利百万大酬宾促销活动,在二楼打出了买300送60元的优惠活动。其中某柜台各以3000元卖出两件商品,其中盈亏均为20%,则该柜台应()。
根据下面的数据定义:ORG10HDAT1DB10DUP(?)DAT2EQU12HDAT3DW56H,$+10数据项$+10的值是:
最新回复
(
0
)