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 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
2010-03-19
36
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 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". 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 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 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 rems. 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.
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 space suits needn’t worry about radiation damage
答案
B
解析
细节理解题。根据文章第二段第四句“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 o
转载请注明原文地址:https://jikaoti.com/ti/H9HMFFFM
0
专业英语四级
相关试题推荐
WhywasJennyunhappyatthebeginningoftheconversation?
RodneyMace,35,ismarriedwithtwoyoungchildren,andisapart-timeteacherofarchitecturalhistory."Iamconstantlysurpr
Tensionwithinafamilyisoftenrelievedoreliminatedwhenthefamilyasawholeisthreatenedby______force.
AlthoughtheUnitedStatescherishesthetraditionitisanationofsmalltownsandwideopenspaces,onlyoneineveryeightA
InBritain,withinthelifetimeofalltheoldpeoplealivetoday,ourlifeexpectancyhasrapidlyshotupfromanaverageoffo
Scientificresearchresultscannowbequickly_____tofactoryproduction.
1 Mostearthquakesoccurwithintheupper15milesoftheearth’ssurface.Butearthquakescananddooccuratalldepthstoab
Whenwilltheydiscusstheagenda?
______eachotherfor10years,theydecidedtomeetthisyear.
Theorder______theprisonerbesetfreearrivedtoolate.
随机试题
A.阿司匹林B.巴比妥C.四环素D.氢氯噻嗪E.鱼精蛋白可导致口服避孕药避孕失败的药物是
中国人口众多,地域辽阔,使得我们具有________的内需市场和分工体系,即使在外部需求受到冲击的情况下,仍然可能通过增加内部的________来保持增长,这已经被全球金融危机后的一系列的事实所证明。由于各地发展仍不平衡,很多地方的经济发展具有很大的潜力,
患儿,男,7岁。受凉后咳嗽、咽痛、流涕2天,诊为上呼吸道感染。近1天持续性右下腹疼痛伴呕吐2次,体温38.8℃。此时首先要进行鉴别的疾病是
以八纲辨证,因劳倦伤气,血失统摄,孕产过多,在妇科引起的病变都属于( )
甲公司与乙公司签订了一份复印机转让合同。甲公司交货后、乙公司发现复印机存在质量问题,如果双方在合同中未约定检验期间,则以下说法正确的是:()
家庭收支平衡规划的核心是建立应急基金,保障个人和家庭生活质量和状态的持续性稳定,是针对家庭财务流动性的管理。()
在国际单位制的基本单位中,质量计量单位的名称和符号分别是()。
()实际上是计时工资的一种转化形式。
华生在以小艾尔伯特为被试的恐惧实验中,采用的研究方法是()
A、Thetaskistofindtwochemicalexperiments.B、Theparticipantsaretheprimaryschoolstudents.C、Thelocationistheiracti
最新回复
(
0
)