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
专升本
Space is a dangerous place, not only because of meteors but also because of rays from the sun and other stars. The atmosphere ag
Space is a dangerous place, not only because of meteors but also because of rays from the sun and other stars. The atmosphere ag
admin
2011-04-26
69
问题
Space is a dangerous place, not only because of meteors but also because of rays from the sun and other stars. The atmosphere again acts as our protective blanket on 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 spacesuits 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". Scientists have reason to think that a man can put up with far more radiation than 0.1 ream without being damaged; the figure of 60 rems 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 (畸形的) 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 reams. 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 no really effective ones have been found so far.
We know from the passage that ______. ( )
选项
A、exposure to even tiny amounts of radiation is fatal
B、the effect of exposure to radiation is slow in coming
C、radiation is avoidable in space exploration
D、astronauts in spacesuits needn’t worry about radiation damage
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/lGqC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
Mostpeople______.Mostofusareright-handedand______.
ItwasMonday,Mrs.Smith’sdogwashungry,buttherewasnotanymeatinthehouse.Consideringthattherewasnobetterwa
It______thepostofficetimeifpeopleaddresslettersproperly.
Areyouconscious______anyreasonwhyheshouldnotbeenrolledinthisuniversity?
Accordingtothepassage,cultureshock______.Themainideaofthispassageisthat______.
Theteacher______thestudentsonatourthroughtheartmuseum.
Forthispart,youaresupposedtowritealetterof100-120wordsbasedonthefollowingsituation.Remembertowriteitclearl
They______onatripintothedesertthefollowingyear.
Accordingtothefirstparagraph,thetaskofeducationisfairlycomplicatedbecause______.Whichofthefollowingpointsis
—Whatdoyouthinkofthetown______?—Oh,itisverybeautiful.
随机试题
关于非结合胆红素下列哪项描述是错误的
符合幼儿期特点的是()。
2009年,甲、乙、丙、丁共同设立A有限责任公司。丙以下列哪一理由提起解散公司的诉讼法院应予受理?(司考.2011.3.27)
某建筑物采用TN-C-S系统供电,建筑物地下室设有与大地绝缘的防水层。PEN线进户后即分为PE线和N线,并打人工接地极将PE线重复接地。变电所系统接地RA和建筑物重复接地RB阻值分别为4Ω及10Ω。各段线路的电阻值如下图所示,为简化计算可忽略工频条件下的回
商业性担保人主要包括()。
下列同定资产中,按规定计提的折旧费用可以在企业所得税税前扣除的是()。
在成本性态分析的基础上,依据业务量、成本和利润之间的联动关系,按照预算期内可能的一系列业务量水平编制的系列预算方法的是()。
下列属于资源管理策略的是()
SQL语句中修改表结构的命令是______。
下列叙述中正确的是()。
最新回复
(
0
)