Space is a dangerous place, not only because of meteorsbut also because of rays from the sun and other stars.The atmosphere again acts ____1____ our protective blanket on ____2____ .Light gets through, and this is essential ____3____ plants to make the food which we ____4____ .Heat, ____5____ , makes our environments tolerable and some ultraviolet rayspenetrate the ____6____ .Cosmic(宇宙的) rays of various kinds come ____7____ the air from outer space, but ____8____ quantities of radiation from the sun are screened off. ____9____ men leave the atmosphere they are ____10____ to this radiation; ____11____ their spacesuits or the walls of their spacecraft, if they are inside, ____12____ prevent a lot of radiation damage.Radiation is the greatest known danger to explorers in ____13____ .Doses of radiation are measured in ____14____ calledrems.We all ____15____ radiation here on earth from the sun, from cosmic rays and from radioactive minerals.The____16____dose of radiation that we receive each year is about two millirems; it ____17____ according toswheresyou live, and this is a very rough estimate.Scientists have reason to think ____18____ a man can ____19____ far more radiation ____20____ without being damaged; the figure of 60 rems has been agreed.
1.A.for B.with C.on D.as
2.A.stars B.sun C.earth D.space
3.A.with B.from C.under D.for
4.A.use B.live C.eat D.get
5.A.again B.also C.besides D.too
6.A.environment B.space C.atmosphere D.earth
7.A.across B.to C.from D.through
8.A.valid B.enormous C.various D.proper
9.A.As soon as B.As well as
C.As much as D.As possible as
10.A.shown B.exposed C.faced D.covered
11.A.but B.because C.so D.so that
12.A.get B.make C.have D.do
13.A.earth B.atmosphere C.space D.environment
14.A.pieces B.units C.parts D.elements
15.A.receive B.accept C.bring D.catch
16.A.conventional B.commonC.general D.normal
17.A.shifts B.converts C.modifies D.varies
18.A.what B.which C.that D.why
19.A.put up with B.keep up with
C.come up with D.catch up with
20.A.from B.than C.as D.away
One kiss One love
中情局长婚外情女主角曝光 始于一起跑步
My furry friend 我最好的朋友
乌坎民主梦幻灭突显基层民主局限
英语课堂游戏:看谁快
Love of a Life time
A Greek to Remember一位值得纪念的希腊人
Watch the world go by与世界擦身而过
You'll never regret it 母爱的真谛
奥巴马为第二个任期规划蓝图
发你一张好人卡
Don’t Allow Your Weaknesses to Limit You
Happy Father's Day 告诉父亲你爱他
黑色星期五 大减价真能拣便宜?
奥巴马竞选背后的策划者
The River of Doubt
IMF:法国必须改革
Each day is special 每一天都特别
A girl's smile 女孩的微笑
标普或因CPDO评级面临集体诉讼
美财政危机带来的压力进一步增加
For girls only 女孩箴言
生活如同为自己打造的工程
美丽的英文
Lex专栏:一切照旧的中资银行
Love Your Life
日本首相承诺加入泛太平洋伙伴关系会谈
Are men romantic? 谁说男人不浪漫?
Two extremes in life 生活中的两极
Disaster on a mountain 山中救援
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