2024年1月24日发(作者：)

2021年12月大学英语四级完形填空:精选练习(3)

Directions: There are 20 blanks in the following passage.

For each blank there are four choices marked [A], [B], [C] and

[D]. You should choose the ONE that best fits into the passage.

Space is a dangerous place, not only because of meteors(流星) but also because of rays from the sun and other

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 rays(紫外线的) penetrate 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 ion is the greatest

known danger to explorers in 13 . Doses of radiation are

measured in 14 called"rems (雷目)". We all 15 radiation here

on earth from the sun, from cosmic rays and from radioactive

" 16 "dose of radiation that we receive each year

is about two millirems; it 17 according toswheresyou live, and

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this is a very rough ists have reason to think

18 a man can 19 far more radiation 20 without being damaged;

the figure of 60 rems has been agreed.

s

nment here

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us s

soon as well as much as possible as

d d

e that

here nment

ts

e

tional l

ts es

up with up with up with up with

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1.【答案】D

【解析】act as“充当、起……作用”；act for“代表、代理”;act

on“按照”。本句意为大气层起到保护伞的作用。

2.【答案】C

【解析】见上题分析。

3.【答案】D

【解析】be essential for“对……来说是首要的、基础的”，固定搭配。

4.【答案】C

【解析】只有eat与先行词food和定语从句搭配。

5.【答案】D

【解析】本句意为：热不仅使我们的生产环境温度适宜，而且紫外线也能穿透大气。also一般紧跟词；besides一般用在句前;too可用在句中，用逗号隔开。

6.【答案】C

【解析】根据上题所讲，penetrate这个动词后面应接atmosphere“大气”这个名词。

7.【答案】D

【解析】这里的come through相当于penetrate，穿透。come across“偶遇”；come to“来到”；come from“来自”。本句意为：各类第 3 页

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来自外部空间的宇宙射线穿透大气层……，故选come through。

8.【答案】B

【解析】Valid有效的；various各种各样的；proper合适的。在四个选项中只有enormous表示“大量的”意思。

9.【答案】A

【解析】as soon as“只要”；as well as“除……之外”；as much

as“和……一样多”；as possible as“尽可能的”。

10.【答案】B

【解析】be exposed to“暴露于”，show“展示”；face“面对”。

11.【答案】A

【解析】本句前半句的意思是：“人们一离开大气层就会接触射线”;后半句意思是：“他们的太空服和太空船会阻止射线造成的损害”。前后应该是转折关系，故用but。

12.【答案】D

【解析】Do +动词原型的结构表示强调谓语动词。

13.【答案】C

【解析】由radiation和explorers可推测，应选space(太空)。本句意为射线是探险者在太空遇见的已知的最大危险。

14.【答案】B

【解析】unit“单位、单元”；element“元素”；part“部分”；piece“碎片”本句意为：射线的多少可以以雷目这个测量单位测量。

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15.【答案】A

【解析】receive表示客观收到;accept表示主观接受。我们受到的辐射并非主观接受。

16.【答案】D

【解析】conventional“传统的”；common“共同的、普通的”；general“一般的、总体的”；normal“正常的”。本句意为：我们每年接受的正常辐射量……，故选normal。

17.【答案】D

【解析】shift“移动”；convert“转换”；modify“修改”；vary“变化”。根据句意，所处地点不同，所受辐射量也不一样……，故选varies.

18.【答案】C

【解析】本句应填入引导宾语从句的代词，而从句不缺少主语和宾语，因而不选择what和which，又加之主句是陈述语气，故选择that。

19.【答案】A

【解析】put up with“忍受”，固定搭配。keep up with和catch

up with意为跟上，come up with意为提出。

20.【答案】B

【解析】more (radiation)后应加than。

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