从句的省略

      从句省略一直是做SC时候很多同学心中的一个痛，all in one上课时间有限，可能没法把不同从句的省略规则都一一拿出来做个横向比较，这里我们就完整地扒一扒常见的从句省略考点。

      1. 状语从句的省略（although, because, when等等这样一些引导词引导的修饰句子的从句）

这种从句里面经常省略从句的主语，如果从句的谓语动词有be动词的话，be动词必须也省略。这种从句省略的前提条件是从句和主句的主语相同。

所以在选项当中遇到这种从句的省略，一定两个步骤走：

       1）把主句主语还原到从句主语当中

       2）看从句还原后逻辑意思是否正确

       以OG2015的第74题的E选项为例：

       Although covering the entire planet, Earth has a crust that is not seamless or stationary, but rather fragmented into mobile semirigid plates.

这个选项当中although 从句就没有主语，所以按照要求还原主句主语以及be动词：Although earth is covering the entire planet ，然后判断逻辑意思，不是earth覆盖星球，而是crust，所以E错了。

类似考点，大家还可以自己分析一下OG2015的124题的D选项。

      2. 比较从句的省略 （than和as引导的从句）

      than/as引导的比较从句后面通常都会省略。省略的原则是：

      1）比较从句谓语与主句谓语相同，可以用do, did或does代替。

      I ate more apples than Li Lei did.

      2）主句和从句都使用be动词，从句可以省略be动词,也可以不省略。

      I am taller than Li Lei (is)

      3）主句谓语动词短语使用“助动词（have, has, had, will）或情态动词（can, could, may, should）+verb”形式时，比较从句往往省略verb，保留助动词或者情态动词。

      I can eat more food than Li Lei can (eat)

      4）比较从句的主语和谓语与主句的主语和谓语相同时，可以全部省略，常常保留状语的介词短语或者状语从句。

      I walk as fast now as (I walked) when I was younger

      5）比较从句的主语与主句主语相同，可以省略。

      The house was as clean as (it) could be.

      OG2015的第94题的正确选项就是一个很好的学习比较从句省略的例子：

      Heating-oil prices are expected to be higher this year than last because refiners are paying about $5 a barrel more for crude oil than they were last year.

      这个句子里面第一个than从句只跟了一个时间last (year)，省略了主语和谓语动词，补充完整的话就是照抄主句的主语和谓语：than heating-oil prices were expected to be last year

      第二个than从句补充完整应该是 than they were paying last year 所以其他几个选项用then they did last year就错了，因为如果用did，前面必须出现pay或者paid。

      大家自己也可以去研究一下og2015的第139题.

      3. 定语从句的省略

      一般定语从句修饰前面的名词，如果名词做从句里面的动词宾语的话，定语从句的引导词可以省略。

      例如og2015的第35题：By 1940, the pilot Jacqueline Cochran held seventeen official national and international speed records, earned at a time when aviation was still so new that many of the planes she flew were 这里的定语从句she flew就是省略了引导词that，因为从句修饰的飞机做flew的宾语。

      Og2015的第63题：When Congress reconvenes, some newly elected members from rural states will try to establish tighter restrictions on the amount of grain farmers will be allowed to grow and to encourage more aggressive sales of United States farm products overseas.这里的定语从句farmers will be allowed to grow省略了引导词that，因为这里的名词amount of grain做的从句动词grow的宾语。

      4. 宾语从句的省略

      宾语从句的that到底能不能省？？先来看一个OG的正确选项：

      Many experts regarded the large increase in credit card borrowing in March not as a sign that households were pressed for cash and forced to borrow, but as a sign that households were confident they could safely handle new debt.

      这里confident后面的句子就是省略了that的宾语从句；再来对比看一组句子，

      Tom told me that he finished his homework last night ,and that he moved on a little more.

      Tom told me that he finished his homework last night ,and he moved on a little more.

       第二句话省了一个that，这样一来导致两个句子的语义不一样了。第一句说的是Tom告诉我了两件事情，第二句话Tom只告诉我了一件事情，并没有告诉我he moved on a little more，这种省略引起了语义变化，肯定是有问题。

       所以得出的结论是：一个宾语从句的时候，最好不要省略，但是官方题出现过省略；如果两个宾语从句平行并列的时候，一定不能省略，这个点经常经常考，切记！

       这样梳理一下知识点，希望对你解决从句省略的题目有所帮助～