5．易与强调句混淆的几个句型

　　(1)It is＋时间＋when ..."当......的时候；时间是......"when 引导的是时间状语从句，主句中的 it 指时间，表语由具体的时间充当。试比较：

　　It was ten o'clock when we got home last night.

　　我们昨晚到家时十点了。(状语从句)

　　It was at ten o'clock that we got home last night.

　　我们昨晚是在十点到家的。

　　此句是强调句，去掉"It was ... that"后句子仍然完整合理，注意that不能改成when。而上句不是强调句。

　　(2)It was/will be ... before ... "过......就......"

　　It was not/will not be ... before ... "不久......就......"主句中的 it 指时间，表语多是long, not long, three days, two weeks等表示"一段时间"的词或短语。试比较：

　　It was three days before he went to Beijing.

　　三天后他就去了北京。

　　It was three days ago that he went to Beijing.

　　他是三天前去的北京。

　　此句是强调句，去掉"It was ... that"后句子仍然完整合理。

　　[即时演练3]　单句语法填空

　　①(2015·湖南高考书面表达)It is the teacher's praise that contributes to my success.

　　②It is either he or you who are (be) in charge of the project and supposed to finish it punctually.

　　③It will not be long before he finishes his job.

　　④It was 5 o'clock when we set off yesterday.

　　Ⅰ.单句语法填空

　　1．It was not just the size of the party last night butwhat it meant to our company that made it unique.

　　2．He was so busy yesterday that it was not until late at night that he finished his work.

　　3．It was only when I reread his poems recently that I began to appreciate their beauty.

　　4．-When did you come back last night?

　　-It was not until 11 o'clock when the party ended.

　　5．Was it on a lonely island that he was saved one month after the boat went down?

6．It is five months since my son went to America.