Part Ⅳ CLOZE ［15 MIN.］ Decide which of the choices given below would best complete the passage if inserted in the corresponding blanks. Mark the best choice for each blank on your answer sheet. The difference between a liquid and a gas is obvious ( 26 ) the conditions of temperature and pressure commonly found at the sur face of the Earth. A liquid can be kept in an open container and ( 27 ) it to the level of a free surface. A gas forms no free surface but ( 28 ) to diffuse throughout the space available; it must ( 29 ) be kept in a closed container, as ( 30 )a planet’s atmosphere. The distinction was a prominent feature of early theories ( 31 )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 held that the two phases are ( 32 ) different kinds o f molecules(分子). The theories now prevailing ( 33 ) a quit e different approach by emphasizing what liquids and gases have in common. They are both forms of matter that have no permanent structure, and they both flow ea sily. They are fluids.
The ( 34 ) similarly of liquids and gases becomes clear ly apparent when the temperature and pressure are raised somewhat.( 35 ) a closed container partially filled with a liquid is heated. The li quid expands or ( 36 ), becomes less dense; some of it evapor ates.( 37 ), the vapor above the liquid surface becomes dense r as the evaporated molecules are added to it. The combination of temperature an d pressure ( 38 ) the densities become equal is ( 3 9 ) the critical point. Above the critical point the liquid and the gas can no longer be ( 40 ); there is a single, undifferentiated fluid phase of uniform density. 26. A. in B. on C. under D. beyond 27. A. fills B. be filled C. filling D. to fill 28. A. intends B. tends C. inclines D. contends 29. A. however B. nevertheless C. so D. therefore 30． A. in the event of B. in the case of C. with a view to D. with reference to 31. A. having described B. described C. describing D. to have described 32. A. made up of B. consisted of C. constituted of D. made from 33. A. apply B. adapt C. take D. conduct 34. A. elementary B. crucial C. rudimentary D. fundamental 35. A. Suppose B. To suppose C. Being supposed D. Supposed 36. A. in a word B. in the meantime C. in other words D. in that case 37. A. Similarly B. In contrast C. Furthermore D. Instead 38. A. on that B. on which C. at that D. at which 39. A. known B. defined C. called D. referred to 40. A. classified B. recognized C. categorized D. distinguished
答案部分短文大意：这篇文章介绍了气体与液体的特性及相关理论。 26．答案：B【试题分析】本题考查对固定搭配的掌握。【详细解答】under与condition搭配，表示“在……条件或状况下”；on与 condition搭配，表示“在……条件下”；in与condition构成习惯短语，表示“身体状况良好”，而be out of condition”则表示“身体状况不好”。 这里是说“在地球表面通常的温度和压强条件下……”，故选项B为正确答案。
30．答案：B【试题分析】本题考查对固定搭配的掌握。【详细解答】in the event of表示“如果发生……，万一……”；in the case of表示“在……的情况下，就……而言”; with a view of或者with a view to，意思是“以……为目的；为……起见”；with reference to意思是“关于”。根据上下文，这里是说“必须将气体存放在一个密封的容器里，如同一颗行星的大气一样。” 故选项B为正确答案。
32．答案：A【试题分析】本题为短语词义与用法辨析题。【详细解答】consist of一般用主动式; be made from一般指某种产品由某种材料制成(但从外表上看不出原材料); be made up of表示“由……组成”。根据上下文理解，此处要求填一“由……组成”的短语，故选项C为正确答案。
36．答案：C【试题分析】本题考查关联词的用法。【详细解答】in a word表示对上文的总结；in the mean time表示“同时”；in that case表示“在那种情况下”；in other words意为“换句话说”。上文的“expands”和后文“becomes less dense”的意思一致，后一句是为了解释说明前一句，故用in other words。
38．答案：D【试题分析】本题考查关系词的用法。【详细解答】本句子意为“使液体和气体密度相同的那个状态下的温度和压力被称作临界点。”句中的“temperature and pressure”是先行词，需要一个关系词引导一个定语从句修饰先行词。特定数值的temperature和pressure与at搭配意为“在某个温度和压力下”。由于that引导定语从句时前面不能有介词，所以正确答案是D。
39．答案：C【试题分析】本题为动词词义及用法辨析题。【详细解答】known的常用结构是be known to be或be known as；defined 常用结构是be defined as；refer to意为“提到，说起”，不用于被动语态；只有called后可直接接主语补语。
