- 5.
- ecies of snake in this area____in danger of being extinguished,and what he is doing _____try to keep this species from dying out.
;is e;is ;are e;are
- A 考查主谓一致
some species of snake 做主语,谓语动词用单数形式 is(类似于a kind of books 的用法,作主语时,谓语要与前面的词对应,即与kind对应;根据下文 this species 说明上文说的是‘某种蛇’也就是一种).
what he is doing 做主语,谓语动词用单数形式 is
此题还应该掌握如下知识:
1. 主语从句做主语,谓语动词通常用单数,但是应该注意what引导的主语从句常常与表语保持一致:
What I need is a book. / What I need are some books.
2. 主语部分有实意动词do 的某种形式时,做表语的不定式常常省掉不定式符号to. 此题中 try 前省掉了 to.