英语完形填空及答案解析.doc

PAGE PAGE 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. 1. A. gases B. pieces C. things D. gas 2. A. timely B. trimmed C. tiny D. topical 3. A. ought B. could C. will D. must 4. A. sky B. atmosphere C. oxygen D. environment 5. A. various B. many C. the D. those 6. A. only B. too C. that D. extremely 7. A. should B. were C. get D. could 8. A. construct B. structure C. piece D. feature 9. A. but B. also C. thus D. nevertheless 10. A. solved B. discovered C. broked D. told 11. A. must B. been C. were D. is 12. A. putting B. pairing C. placing D. preparing 13. A. while B. when C. therefore D. also 14. A. piece B. type C. atom D. measure 15. A. from B. in C. of D. for 16. A. then B. so C. by D. that 17. A. from B. in C. to D. for 18. A. are B. wouldn’t C. always D. never 19. A. describe B. unit C. mix D. reveal 20. A. different B. usual