17年英语专四完形填空训练1 Thedifferencebetweenaliquidandagasisobviousundertheconditionsoftemperatureandpressu下面是小编为大家整理的2023年度17年英语专四完形填空训练（2023年）,供大家参考。
17年英语专四完形填空训练1
The difference between a liquid and a gas is obvious under the conditions of temperature and pressure commonly found at the surface of the Earth. A liquid can be kept in an open container and fill it to the level of a free surface. A gas forms no free surface but tends to diffuse throughout the __11__ available; it must therefore be kept in a closed container or held by a gravitational field, as in the __12__ of a planet"s atmosphere. The distinction was a __13__ feature of early theories describing the phases of matter. In the nineteenth century, for example, one theory maintained that a liquid could be "dissolved" in a vapor without losing its identity, and another theory __14__ that the two phases are made up of different kinds of molecules. The theories now prevailing take a quite different approach by emphasizing what liquids and gases have in__15__They are both forms of matter that have no__16__ structure, and they both flow readily.
The fundamental similarity of liquids and gases becomes clearly apparent when the temperature and pressure are __17__somewhat. Suppose a closed container__18__ filled with a liquid is heated. The liquid expands, or in other words becomes less dense; some of it evaporates. In contrast, the vapor above the liquid surface becomes denser as the evaporated molecules are__19__ to it. The combination of temperature and pressure at which the densities become __20__is called the critical point.
A. added B. case C.prominent D.held
E. equal F. partially G.example H.previous
I. space J.lifted K.permanent L.particularly
M. extended N. raised 0.common
参考答案
II. I 12. B 13. C 14. D 15. O 16. K 17. N 18. F 19. A 20. E
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