托福语法讲解：状语从句

 状语从句是从句中的一大类，在考题中更是频繁出现，它的主要功能是作主句的状语，由完整的主谓句构成。状语从句和主句在语法上关系并不紧密，但在逻辑上是不可分割的

　　考点一 分类及主要引导词

　　1. 时间状语从句

　　主要引导词：when, whenever, before, after, until, while, since, once, so long as, as soon as, the moment, every time, as, next time

　　I will call you after I get to the company.

　　I don't call her until I get to the company.

　　Every time I feel lonely, she comes to talk to me.

　　2. 地点状语从句

　　主要引导词：where, wherever

　　Wherever you go, I will be right here waiting for you.

　　3. 原因状语从句

　　主要引导词：because, as, since, considering that, now that, not that, seeing that

　　注意：in that是书面语中原因状语从句的引导词，相当于because, 在填空题中曾经出现

　　Now that it is raining, we'd better cancal the meeting.

　　4. 目的状语从句

　　主要引导词：so that, in order that, for fear that, in case, lest

　　5. 结果状语从句

　　主要引导词：so…that, so that, such…that

　　注意：so…that句式和too…to句式的区别是重要考点之一，so…that接从句；too…to接不定式

　　The old lady is so generous that a lot of people admire her.

　　She is too young to resist it.

　　6. 条件状语从句

　　主要引导词：if, unless, in case, so long as, on condition (that), provided (that)

　　7. 让步状语从句

　　主要引导词：though, although, no matter, even if, even though, however, whatever

　　注意though, although等都不能够与but连用

　　例题：

　　(1)

　　Anthropology¹ is a science ----anthropologists use a rigorous set of methods and techniques to document observations that can be checked by others.

　　(A) in that

　　(B) that in

　　(C) that

　　(D) in

　　答案：A

　　解释：空白处前后均是完整的主谓句, 意思上后者是对前者的解释说明, 推知需填入从句引导词, in that是一特殊的状语从句引导词, 表示原因, 与此句意思吻合

　　(2)

　　Gorillas² are quiet animals, ----they are able to make about twenty different sounds.

　　(A) how

　　(B) in spite of

　　(C) because of

　　(D) even though

　　答案：D

　　解释：空白前后都是完整的主谓句，需填的一定是连词，可首先排除BC,A引导的宾语从句不能接在表语后，只有D正确，构成状语从句

　　考点二 状语从句中的省略

　　部分状语从句可以省略，在填空题中时有出现

　　如：Although defeated, he did not lose heart. (从句中省略了he was)

　　If informed timely, I wouldn't have missed the meeting. (从句中省略了I were)

　　例题：

　　(1)

　　----relatively costly³, the diesel⁴ engine is highly efficient and needs servicing infrequently

　　(A) Even

　　(B) It is

　　(C) Even though

　　(D) There is

　　答案：C

　　解释：逗号后是完整的句子, 缺少的可能是从句或状语的一部分, B、D是主谓结构, 肯定不对; A 是副词, 为甚至之意, 放在原句中讲不通; C 是尽管的意思, 实际上省略了状语从句的主谓语it is, 符合题意. 还需注意的是costly是形容词而不是副词

　　(2)

　　Although ---- rigid⁵, bones exhibit a degree of elasticity⁶ that enables the skeleton to withstand considerable impact.

　　(A) apparently

　　(B) are apparently

　　(C) apparently their

　　(D) are they apparently

　　答案：A

　　解释：although是让步状语从句引导词，空格处需要从句的主谓语，B缺少主语，D不应倒装，可先排除；their不能修饰形容词rigid，B也可排除；A是从句的省略式，相当于Although they are apparently rigid

1 anthropology   

n.人类学

参考例句：

• I believe he has started reading up anthropology.我相信他已开始深入研究人类学。
• Social anthropology is centrally concerned with the diversity of culture.社会人类学主要关于文化多样性。

2 gorillas   

n.大猩猩( gorilla的名词复数 )；暴徒，打手

参考例句：

• the similitude between humans and gorillas 人类和大猩猩的相像
• Each family of gorillas is led by a great silverbacked patriarch. 每个大星星家族都由一个魁梧的、长着银色被毛的族长带领着。 来自《简明英汉词典》

3 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。

4 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。

5 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。

6 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。