一、一般强调结构
强调结构为： It is (was)…that…。
它可以用来强调句中的某些成分， 如主语(从句)、宾语(从句)、状语(从句)等。
如强调主语或宾语， 则that可用who(指人)， whom或which(指物)来代替；
如强调的是状语， 则不能用when, where等代替， 只能用that。
注意， 强调结构不能用来强调谓语动词和表语。
It was my uncle that (who) sent me the parcel。
It is the article that (which) they discussed last week。
It was because he was too careless that he broke all the glasses。
It is in this room that I was born 30 years ago。
