宾语从句概念：见SB91 1.由that 引导，可以省略。 I heard that he joined the party.

2.由what, whether, if 连词引导的宾语从句。 Could you explain to me what has happened to her? I wonder whether/if you can change this note for me.

3.连接代词who, whose, what ,which, whoever, whatever, whichever Pay attention to what the doctor said, will you ? She would give whoever needs help a warm support.