一．IT句型
1.It +be + 一段时间 +before 从句
2.It + be+ 一段时间 + since从句
3.It + be+ 时间 + when从句
4.It + be+ 强调部分 + that从句
注意:It was at this shop that you bought the watch, wasn’t it ?
Eg:1.It was already 8 o’clock _________ we got home.
2.It will be three hours _________ he arrives at the airport.
3.It is ten years _________ I last saw you.
