强调句型
It is /was +被强调部分+that...
例：It was I who wrote to my uncle yesterday.
是我昨天给我叔叔写信的。
Is/was it + 被强调部分 + that ...
例：Was it your brother that you met in the street?
在街上你遇到的是你兄弟吗?
Where/who/what/how等特殊疑问词 + is/was it that ...
例：How is it that you will go to visit her tomorrow?
明天你到底如何去看望她?
do/does/did +谓语动词
例：They do know the place well.
他们的确很了解那个地方。
