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
77
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://kaotiyun.com/show/9v9K777K
0
专业英语四级
相关试题推荐
Acomputerisamachinedesignedtoperformworkmathematicallyandtostoreandselectinformationthathasbeenfedintoit.I
EverypeoplehasitsownspecialwordsandexpressionsliketheAmericanexpression"onthewagon".Itmeansapersonwhonolo
______isannouncedinthepapers,ourcountryhaslaunchedalarge-scalemovementagainstsmugglingandfraudulentactivitiesi
Thejudgerdoesn’tknowwhetherthewitnessistellingthetruth,buthewill______it.
Whypeoplework?Undoubtedlyyouhaveperiodicallyaskedyourselfthesamequestion,perhapsfocusedonwhyyouhavetowork."S
Altogetherhowmanypeoplewereinjuredduringtheviolence?
Thesevariedracialgroupshavelearnedtolivetogetherinpeaceand______,settinganexamplewellworthfollowing.
Themillionsofcalculationsinvolved,hadtheybeendonebyhand,______allpracticalvaluebythetimetheywerefinished.
Thelifepaceinbigcitiesrequirespeopletobeabletotravelefficientlyfromoneplacetoanother.Somepeopleseemtothin
Howshouldaparentwithstrongpoliticalopinionstalktotheirchildabouttheirviews?Ifyoulistentothepollsters,you’re
随机试题
改变病情抗风湿药治疗类风湿关节炎的作用包括
MRI在头颅蝶鞍层面能显示第几对脑神经
患者,男,65岁。近8年来夜尿由2~3次渐增至4~5次,排尿踌躇,涩滞不畅,昨晚发生小便欲解不能,小腹急满胀痛,舌黯、脉细涩,直肠指诊前列腺增大约5.5×4.1×3.3cm,中央沟消失,质韧有弹性,光滑无结节。首先考虑的疾病是()
若微机在工作过程中电源突然中断,则计算机中()全部丢失,再次通电后也不能恢复。
企业长期股权投资在成本法核算下,如果被投资单位宣告分派的现金股利,属于被投资单位接受投资后产生的累积净利润的分配额,则应确认投资收益。()
由于被告无力支付律师费,也无法为自己辩护,因此法院委派一名律师为其辩护,这种情况下,律师与被告形成的代理关系为()。
收件人签收文书应在()上签字。
新三民主义与中共民主革命纲领的根本区别在于()。
Note:Whenmorethanoneanswerisrequired,thesemaybegiveninanyorder.Somechoicesmayberequiredmorethanonce.I
CanadianauthoritiesrelayedthatsuspiciontotheU.S.CoastGuard,whichdispatchedacuttertointerceptthevessel.Aftera
最新回复
(
0
)