[语法初识]

原句感知 自主探究 ①What we find out from space research is important for us on Earth.

②It's well­known that the ancient Chinese invented the rocket.

③We think it probable that he is dead.

④The teacher showed us the controls of the spacecraft and explained how gravity worked.

⑤They insisted that everyone (should) come to the party.

⑥The proposal that we (should) import more equipment from abroad is to be discussed at the meeting.

⑦I have no idea when she will be back.

⑧The question remains whether they will be able to help us.

⑨The problem is who we can get to replace her. (1)句①②为主语从句，句③④⑤为宾语从句，句⑥⑦为同位语从句，句⑧⑨为表语从句。

(2)句②③⑥⑧中的引导词为连接词，在从句中不作成分，句①⑨中的引导词为连接代词，句④⑦中的引导词为连接副词。

(3)句②③中使用了it作形式主语或形式宾语，而真正的主语从句或宾语从句后置。

(4)句⑤中的that可省略，其他句中的that一般不可省略。

(5)句⑤⑥中的从句使用了虚拟语气。 　　

　　[语法剖析]

　　名词性从句在功能上相当于名词，可作主语、宾语、表语和同位语。因此名词性从句可分别称为主语从句、宾语从句、表语从句和同位语从句。名词性从句必须使用陈述语序，即"主语＋谓语"的语序。引导名词性从句的连接词可分为三类：连接词：that, whether, if(不充当从句的任何成分)；连接代词：what, whatever, who, whoever, whom, whose, which, whichever；连接副词：when, where, how, why。