Question

it was a lucky accident that we see each other

It was a lucky accident that we saw each other
这是个什么从句?that在这做的是什么成分?还是不做成分

Answer 1

应该是强调句.
强调的是a lucky accident （即It is...that 之间非谓语内容）,并且去掉(It+was/is+who/whom/that)这个结构后句子仍能成立.
例:All boys held a meeting in the classroom yesterday.
（强调all the members） It was All boys that held a meeting in the classroom yesterday.
（强调a meeting ）It was a meeting that all boys held in the classroom yesterday.
（强调in the classroom ）It was in the classroom that all the boys held a meeting yesterday.
（强调yesterday）It was yesterday that all the boys held a meeting in the classroom .
It 作形式主语代替主语从句,主要是为了平衡句子结构,主语从句的连接词没有变化.而it引导的强调句则是对句子某一部分进行强调,无论强调的是什么成分,都可用连词that.被强调部分指人是也可用who/whom.主语从句：It is +形容词/名词/某些动词ed + that 从句.it作形式主语