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
Space is a dangerous place, not only because of meteors (陨星) but also because of rays from the sun and other stars. The atmosphe
Space is a dangerous place, not only because of meteors (陨星) but also because of rays from the sun and other stars. The atmosphe
admin
2012-09-19
37
问题
Space is a dangerous place, not only because of meteors (陨星) but also because of rays from the sun and other stars. The atmosphere again acts as our protective blanket on the earth. Light gets through, and this is essential for plants to make the food which we eat. Heat, too, makes our environment endurable. Various kinds of rays come through the air from outer space, but enormous quantities of radiation from the sun are screened off. As soon as men leave the atmosphere they are exposed to this radiation but their space suits or the walls of their spacecraft, if they are inside, do prevent a lot of radiation damage.
Radiation is the greatest known danger to explorers in space. The unit of radiation is called "rem (雷姆)". Scientists have reason to think that a man can put up with far more radiation than 0.1 rem without being damaged; the figure of 60 rem has been agreed on. The trouble is that it is extremely difficult to be sure about radiation damage---a person may feel perfectly well, but the cells of his or her sex organs may be damaged, and this will not be discovered until the birth of deformed children or even grandchildren. Missions of the Apollo flights have had to cross belts of high radiation and, during the outward and return journeys, the Apollo crew accumulated a large amount of rem. So far, no dangerous amounts of radiation have been reported, but the Apollo missions have been quite short. We simply do not know yet how men are going to get on when they spend weeks and months outside the protection of the atmosphere, working in a space laboratory. Drugs might help to decrease the damage done by radiation, but not really effective ones have been found so far.
It can be inferred from the passage that______.
选项
A、the Apollo mission was very successful
B、protection from space radiation is no easy job
C、astronauts will have detormed children or grandchildren
D、radiation is not a threat to well-protected space explorers
答案
B
解析
根据文章最后一句“Drugs might help to decrease the damage done by radiation,but not really effective ones have been found so far.”可知答案为B项。
转载请注明原文地址:https://kaotiyun.com/show/kg57777K
0
大学英语四级
相关试题推荐
Complainingaboutfaultygoodsorbadservicearenevereasy.【M1】______Mostpeopledislikemakingafuss.Butifsome
Complainingaboutfaultygoodsorbadservicearenevereasy.【M1】______Mostpeopledislikemakingafuss.Butifsome
Nothingcanbewasted,andweare____________(从不为有多余的食物困扰)becausewehaveneverhadany.
A、Becauseheisapolitician.B、Becauseheisabusinessman.C、Becausehetravelsbyair.D、Becausehehastoattenddifferentm
A、Becausethiskindofsnakeisoftenfoundinsidehomes.B、Becausethiskindofsnakelivesincultivatedareas.C、Becausethis
A、Becauseshedoesn’tdrinkcoffee.B、Becauseshehasaplanetocatch.C、Becauseshehastogotoalesson.D、Becauseshedoesn
Therehadseemednoanyoftidingovertheeconomiccrisisintowhichwewerenow______.
Adviceto"sleeponit"couldbewellfounded,scientistssay.Afteragoodnight’ssleep,aproblemthatseemedinsurmountable
Adviceto"sleeponit"couldbewellfounded,scientistssay.Afteragoodnight’ssleep,aproblemthatseemedinsurmountable
随机试题
A.肺炎克雷伯杆菌B.金黄色葡萄球菌C.肺炎链球菌D.肺炎支原体E.嗜肺军团菌引起肺外表现最多的致病菌为
骨髓涂片中网状细胞、浆细胞、组织嗜碱细胞、淋巴细胞等增多见于
A.新药申请B.进口药品申请C.再注册申请D.补充申请根据《药品注册管理办法》(局令28号),进口药品申请批准后,改变、增加或者取消原批准事项的注册申请是()。
《住宅使用说明书》应当对住宅的结构、性能和各部位的类型、性能、标准等作出说明,并提出使用注意事项,一般应包含()。
进口许可证的有效期为( )。
具有交叉领导系统的组织结构形式是()。
近年来,我国经贸大国地位进一步巩固,经贸强国建设步伐加快,已成为全球()大消费市场、()贸易大国。
2016年上半年,北京市六大高端产业功能区(以下简称“六高”)规模以上法人单位实现收入28811.4亿元,占全市的比重超过五成(51.5%),较上年同期提高2.9个百分点。其中,工业实现收入占全市工业的比重超过六成(62.4%),较上年同期提高2.3个百分
一个非条件宏,运行时系统会______。
______intooceansandriversisaseriousformofpollution.
最新回复
(
0
)