英语四级语法200条之必须使用完成时态的结构

英语四级语法 200 条之必须使用完成时态的结构 It (This, This evening, yesterday...) is (was, will be) first (second, third...) time (day, month...)...结构中的从句，要求用完成时态。 【例如】 Is this the first time you've been to Beijing?This is the eighth month that I have been out of work.This is the second time that the goods produced by our factory have been shown in the International Exhibition.在 no sooner…than, hardly/barely/scarcely… when,等的句型中，主句要用过去完成时。 【例如】 No sooner had he seen me than he left the room.Hardly had the helicopter landed when the waiting crowd ran toward it.Scarcely had I seen the lightning when I heard a clap of thunder.