大学英语1-7单元练习答案.docVIP

Unit 1 Key to Text A Ex. 1 1. C 2. C 3. B 4. D 5. B Ex. 2 1. The ocean organisms settle down into the ooze underlying shallow arms of the ocean under conditions of oxygen shortage. Then its fat accumulates, is trapped under further layers of ooze, undergoes minor rearrangements of atoms and finally is petroleum. 2. On the surface of porous rocks and in a slowly accumulating pool below the nonporous rocks. 3. Because internal combustion engines were developed, which were powered by the explosion of mixtures of air and inflammable vapors and the most convenient inflammable vapor was that derived from gasoline, a petroleum fraction. 4. (1) Petroleum exists on Earth in far smaller quantities than coal does. (2) Petroleum is not nearly so evenly distributed as coal is. 5. Its enormous consumption of petroleum is making it an oil importer. 6. The political problems already caused by petroleum. Ex. 3 1. A 2. C 3. D 4. A 5. B 6. A 7. A 8. B 9. B 10. D Ex. 4 1. organic 2. originate 3. decompose 4. rearrangement 5. overlain 6. prospector 7. inflammable 8. substantial 9. complication 10. consumption Ex. 5 1. C 2. A 3. A 4. D 5. B 6. C 7. A 8. C 9. C 10. D 11. D 12. C 13. C 14. A 15. D 16. C 17. B 18. A 19. B 20. D Ex. 6 1. sedimentary rocks 2. petroleum reserves 3. internal combustion engines 4. the boiling point 5. fatty substance 6. 少量 7. 石油馏分 8. 易燃蒸汽 9. 地质结构 10. 在……领土 Ex. 7 1. 含有石油的岩石几乎都来源于海洋，所以形成石油的有机物一定是海洋生物，而不是树木。 2. 其脂肪不是分解腐烂，而是逐渐积聚，并在深层的淤泥里圈闭起来，进而经过细微的原子重组，最终形成石油。 3. 一旦获得石油，可以通过地上管道运输，而不必象煤一样，由运货车经过繁重的装卸任务来运输。 4. 这种内燃机与蒸汽机相比，机身小巧，可以瞬间启动；而蒸汽机需要一定时间，等待储水加热到沸点。 5. 石油相对于煤的便利却被另一个事实所抵消：地球上石油的数量比煤少得多。 Ex. 8 1. As is known to all, water consists of hydrogen and oxygen atoms. 2. The myriads of living creatures beneath the sea form the colorful underground world. 3. It is impossible to be dependent on import to develop our national economy. 4. Fuel derived from municipal