1.that引導的定語從句和同位語從句
The news that he had landed on the Moon spread all over the school campus.
他在月球上登陸的消息傳遍了校園。(同位語從句:that只起連接作用,不可省略。)
The news that we heard spread all over the school campus.
我們聽到的消息傳遍了校園。(定語從句:that作heard的賓語,可省略)
2.what,how,whether不能用于引導定語從句,但可引導同位從句
Have you any idea what time it starts? 你知道什么時候開始嗎?
You have no idea how worried I was.你不知道我多著急。
There is some doubt whether he will come.他是否來還不一定。