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 (流星) but also because of rays from the sun and other stars. The atmosphe
Space is a dangerous place, not only because of meteors (流星) but also because of rays from the sun and other stars. The atmosphe
admin
2012-07-17
65
问题
Space is a dangerous place, not only because of meteors (流星) 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 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 (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 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 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.
According to the first paragraph, the atmosphere is essential to man in that______.
选项
A、it protects him against the harmful rays from space
B、it provides sufficient light for plant growth
C、it supplies the heat necessary for human survival
D、it screens off the falling meteors
答案
A
解析
本题问按照文章第一段的内容,大气层对人类非常重要的原因是什么。仔细阅读第一段内容可知,太空是个危险的地方,不仅流星四布,且有太阳和其他星体的辐射。大气层对地球起了一种保护作用。一旦人们离开大气层,就会直接暴露在太阳辐射之中。我们不难看出本题的正确答案应是A“大气层可以保护人类免受太阳辐射的伤害”。
转载请注明原文地址:https://kaotiyun.com/show/p6XO777K
0
在职攻硕英语联考
相关试题推荐
Effortstoreachtheinjuredmenhavebeen______becauseofasuddendeteriorationinweatherconditions.
Iwanttotalkaboutallthesepointsin______orderofimportance.
Thegreatchariotofsociety,whichforsolonghadrundownthegentleslopeoftradition,nowfounditselfpoweredbyaninter
Thegreatchariotofsociety,whichforsolonghadrundownthegentleslopeoftradition,nowfounditselfpoweredbyaninter
Thegreatchariotofsociety,whichforsolonghadrundownthegentleslopeoftradition,nowfounditselfpoweredbyaninter
Thegreatchariotofsociety,whichforsolonghadrundownthegentleslopeoftradition,nowfounditselfpoweredbyaninter
Thegreatchariotofsociety,whichforsolonghadrundownthegentleslopeoftradition,nowfounditselfpoweredbyaninter
Strictsanitaryproceduresformulatedbyourmunicipalgovernmenthelpto______out-breaksofdiseases.
Aperson’shomeisasmuchareflectionofhispersonalityastheclotheshewears,thefoodheeatsandthefriendswithwhomh
AbudgetapprovedbytheEuropeanParliamentfortheEuropeanEconomicCommunitywasdeclaredadoptedTuesdaydespiteopposition
随机试题
男,63岁。心尖区可闻及收缩中晚期吹风样杂音及喀喇音,超声心动图可见二尖瓣前叶CD段呈吊床样波形,最可能的诊断是()
当今时代的潮流是( )。
校准剂量点一般是照射野内指定的测量点,该点位于
患者男,65岁,因劳力性胸闷2年,加重3天入院。既往高血压史10年,2型糖尿病4年。查体:神清,血压150/100mmHg,心率80次/分,心界叩诊向左下扩大,听诊心音有力,未闻及杂音。双肺呼吸音清。双下肢轻度凹陷性水肿。发作时心电图示V4~V6、I和aV
脉诊的"寻"法是指()
患者刘某胸痛、咳嗽,低烧20余天。诊断为肺结核而住进传染病区,应执行
在某项目的评标中,某施工单位的投标报价为5000万元人民币,考虑其工期提前获得优惠200万元人民币,评标价为4800万元人民币。该施工单位中标后,招标人要求其压低报价,出于长期合作等因素的考虑,施工单位同意了招标人的要求,双方按照4900万元人民币的价格另
现金流量表的“现金”单指库存现金。()
税务师在审核企业金融商品转让业务的增值税时,下列说法错误的是()。
A、InBoston.B、inConcord.C、InLexington.D、InBritain.A
最新回复
(
0
)