1英语完形填空及解析Dalton wondered why the heavier and lighter gases in the atmosphere did not separate as oil and water do. He finally concluded that the constituent _1_ must exist in the form of _2_ particles or atoms and that these _3_ be completely mixed together in the _4_.This threw a new light in _5_ laws of definite proportions. It was _6_ necessary to suppose that the atoms _7_ combinesintos small groups of uniform _8_ and so form more complex substance; _9_ the mystery of this law was _10_. Dalton suggested, for example, that carbon monoxide _11_ formed by the one with one _12_ of atoms of carbon and oxygen, _13_ carbon dioxide results from a single _14_ of carbon uniting with two atoms _15_ oxygen. Assuming this to be true, _16_ the definite proportions of Prouts law (_17_ all chemical compounds the different constituents _18_ enter in unvarying proportions) would naturally _19_ the relative weights of the many _20_ kinds of atoms.21. A. gases B. pieces C. things D. gas2. A. timely B. trimmed C. tiny D. topical3. A. ought B. could C. will D. must4. A. sky B. atmosphere C. oxygen D. environment5. A. various B. many C. the D. those6. A. only B. too C. that D. extremely7. A. should B. were C. get D. could8. A. construct B. structure C. piece D. feature9. A. but B. also C. thus D. nevertheless10. A. solved B. discovered C. broked D. told11. A. must B. been C. were D. is12. A. putting B. pairing C. placing D. preparing13. A. while B. when C. therefore D. also14. A. piece B. type C. atom D. measure15. A. from B. in C. of D. for16. A. then B. so C. by D. that317. A. from B. in C. to D. for18. A. are B. wouldnt C. always D. never19. A. describe B. unit C. mix D. reveal20. A. different B. usual C. important D. chemical解析1.【答案】A【解析】根据上文中的 heavier and lighter gases 可以确定,本空中应填入“组成的气体” ，即 constituent gases。2.【答案】C【解析】根据句子意思判断,句中的词意为微粒的意思，选项 C.tiny 合乎题意。3.【答案】D【解析】情态动词 must 在这里是“必定、必须”的意思。4.【答案】B【解析】sky 意为“天空” ，atmosphere 意为“大气”, oxygen 意为“氧气”, environment 意为“环境”,只有 B 项正确。45.【答案】C【解析】这帮助解释了大气组成气体的比例确定原理。因为是特指这一原理，用定冠词 the。6.【答案】A【解析】only necessary 的意思是“仅仅是必要” 。故 A正确。7.【答案】D【解析】根据句子意思判断, could 是“能够”的意思。8.【答案】B【解析】根据句子意思判断,这里需要“结构”这个词，而 B 合乎题意。9.【答案】C【解析】but ，nevertheless 表示转折意为“但是” ， “然而”;thus 意为“因此” ，如 There has been no rain. Thus, the crops are likely to suffer.一直没有下雨，因此庄稼可能会受害。这里与上文有因果关系，故应选 C。10.【答案 】A【解析】solve 相当于 find a solution or an answer to,意为“解决” 、 “解开”,如: solve a problem (a puzzle, a mystery);discover 相当于 find something existing but not known before,意为5“发现”,如: discover a place (a fact, the truth)。因此应选 A。11.【答案 】D【解析】因为是表一般规律，又是单数，所以用 is 这个词。12.【答案 】B【解析】Pair 这里是“匹配，配成双”的意思。13.【答案 】A【解析】while 表示对比。如：Some substances are soluble, while others are not.一些物质是可溶的，而另一些物质是不可溶的。14.【答案 】C【解析】根据句子意思判断, atom 正确。15.【答案 】C【解析】of 表示“含量，分量” 。16.【答案 】A【解析】then 的意思是 next, after that。17.【答案 】D【解析】for 的意思是“对于，就而言” 。18.【答案 】C【解析】根据句子意思判断。19.【答案 】B6【解析】describe 意为“描述”;unite 意为“结合，合并”;mix 意为“(不同的东西) 混合在一起” ，如：mix flour and water;reveal 意为“揭露，揭示” 。20.【答案 】A【解析】根据句子意思判断.The rocket engine, with its steady roar like that of a waterfall or a thunderstorm, is an impressive symbol of the new space age. Rocket engines have _1_ powerful enough to shoot astronauts _2_ the earths gravitational pull and _3_ them on the moon. We have now become _4_ space.Impressive and complex _5_ it may appear, the rocket, which was _6_ in China over 800 years _7_, is a relatively simple device. Fuel that is _8_ in the rocket engine changes _9_ gas. The hot and rapidly _10_ gas must escape, but it can do so only _11_ an opening that _12_ backward. As the gas is _13_ with great force, it _14_ the rocket in the _15_ direction. Like the kick of a gun _16_ it is fired, it _17_ the laws of nature _18_ by Sir Isaac Newton when he discovered that “_19_ every action, there is _20_ equal and 7opposite reaction.”1. A. shown B. been C. appeared D. proved2. A. against B. despite C. beyond D. from3. A. send B. land C. take D. carry4. A. travelers B. astronauts C. researchers D. explorers5. A. that B. so C. as D. sometimes6. A. made B. discovered C. developed D. invented7. A. in advance B. before C. earlier D. ago8. A. round B. contained C. stored D. burned9. A. as B. into C. for D. the10. A. heating B. escaping C. expanding D. conducting11. A. in B. at C. by D. through12. A. turns B. goes C. faces D. directs13. A. transmitted B. dispersed C. erected D. radiated14. A. attracts B. leads C. pulls D. pushes15. A. same B. other C. opposite D. wrong16. A. that B. when C. if D. although817. A. states B. proves C. follows D. breaks18. A. described B. discussed C. considered D. made19. A. like B. as C. with D. for20. A. no B. an C. another D. the 解析1.【答案】D【解析】因其后接形容词 powerful 作表语故应填系词。shown 不是系词;been 和 appeared 虽可作系词但与句意不符;而 proved 可作系词，意为“证明是” ，符合句意。2.【答案】C【解析】根据意