外研版(2019)高中英语必修三 Unit 2 知识点总结

外研版（2019）高中英语必修三Unit 2 知识点总结

一、重点语法知识讲解：

1.All can do is (to)do---我能做的是---当主语部分含有动词do的某种形式时，作表语的不定式可以省略to . all I can do=all that I can do=what I can do ;all 后接that

引导的定语从句，that在从句中作宾语，可以省略，all that---=what---

eg.All I can do is ride a tricycle and make money for the students---

2.动名词短语+is+what引导的表语从句；动名词短语用作主语，谓语动词用单数形式what---=all that---=the things that---=anything that---结论：what引导的名词性从句=先行词+that引导的定语从句

eg. Knowing that the kids now have money for school is what keeps me going and gives me more energy.

3.so---that---:如此---以至于---so后接形容词或副词，such后接名词；so/such---置于句首时，该句用部分倒装，that---不倒装

eg. So well have the kids done that they deserve our praise and thanks.

so---that只引导结果状语从句so that 引导结果状语从句和目的状语从句

4.not only---but also---不仅---而且---，谓语应和后面的主语在人称和数上保持一致，遵循就近原则；not only位于句首时，not only 后要用部分倒装but also不倒装eg. Not only do the teachers have their own ideas on the matter ,but the students have theirs too.

5.have/has been doing:表示动作从某一时间开始，一直持续到现在，或者刚刚终止，或者可能仍然要继续下去。强调动作、行为本身未完成。have/has done表

示事情发生在过去，并一直持续到现在，且过去发生的动作对现在有一定影响。现在完成时强调动作、行为的结果、影响。

6.as引导状语从句和定语从句：as引导时间状语从句，强调动作同时性。随着

as引导原因状语从句。由于as引导让步状语从句。尽管，虽然（从句须倒装）as引导方式状语。以---方式。as引导比较状语从句。像---一样

eg. As our car approached Mount Huang, it slowed down.

It is important to pay your electricity bill on time ,as late payments may affect

your credit.

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