专业四八级-填空题常考结构 7

十一、状语从句省略结构 Metals expand when they are heated. Metals expand 是主句；when they are heated 是状语从句。但是这个状语从句中可以省略掉they are, 句子变成：Metals expand when heated. 但是并不是所有的状语从句都可以这么省略。这种省略从句主语的方式理论上需要满足以下两个条件：

　　　　第一、从句主语和主句主语必须保持一致；　　　　第二、从句的谓语必须是be动词，主语和be动词同进同出，　　　　　　　比如上面的they和are要么同时省略，要么同时保留。

例1：Although___rigid, bones exhibit a degree of elasticity² that enables the skeleton to withstand considerable impact. 　　　(A) apparently³ 　　　(B) are apparently 　　　(C) apparently their 　　　(D) are they apparently 分析：连词although通常引导主谓完整的状语从句，当从句主语与主句主语相同、从句谓语又为系表结构时，则可省略主语和连系动词，故正确答案为（A）。Although apparently rigid¹ = Although bones are apparently rigid, 注意bones和are必须同时省略。

因此，我们从上面的例题中来分析一下填空题中状语从句省略以后的形式：　　though, although, even thought, while, If, when等为引导状语从句的词；　　这些词后面一定+形容词(分词)，主句（注意逗号的后面是主句，前面是从句）

例2：All marble is composed of crystals of the minerals calcite or dolomite, ___, are perfectly⁴ white. 　　　(A) when, pure which 　　　(B) when, which pure 　　　(C) which, pure when 　　　(D) which, when pure 分析：空格前是个完整的句子，空格后是系表结构，空格处显然缺非限定性定语从句的引导词兼作从句主语。（A）、（B）不引导非限定性定语从句，可首先排除。（C）中的pure和when位置错了，故选（D）。注意when pure是插入语，同时也是省略用法when they are pure；which are perfectly white, 状语从句省略结构，

例3：___relatively costly⁵, the diesel⁶ engine is highly efficient and needs servicing infrequently 　　　(A) Even 　　　(B) It is 　　　(C) Even though 　　 (D) There is 分析：B和D填入后，都是构成两个主句，不对；Even though则引导状语从句，even though it is, 这里it is 已经省略。

1 rigid   

adj.严格的，死板的；刚硬的，僵硬的

参考例句：

• She became as rigid as adamant.她变得如顽石般的固执。
• The examination was so rigid that nearly all aspirants were ruled out.考试很严，几乎所有的考生都被淘汰了。

2 elasticity   

n.弹性，伸缩力

参考例句：

• The skin eventually loses its elasticity.皮肤最终会失去弹性。
• Every sort of spring has a definite elasticity.每一种弹簧都有一定的弹性。

3 apparently   

adv.显然地；表面上，似乎

参考例句：

• An apparently blind alley leads suddenly into an open space.山穷水尽，豁然开朗。
• He was apparently much surprised at the news.他对那个消息显然感到十分惊异。

4 perfectly   

adv.完美地，无可非议地，彻底地

参考例句：

• The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
• Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。

5 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

6 diesel   

n.柴油发动机，内燃机

参考例句：

• We experimented with diesel engines to drive the pumps.我们试着用柴油机来带动水泵。
• My tractor operates on diesel oil.我的那台拖拉机用柴油开动。