UNIT 4ASTRONOMY:the science of the stars
语法探究
Teachin g aims: Grasp the attributive clause and use it freely
课前自学（ SBP29 Discov ering useful structu res parts2-3）
语法知识精讲
主语从句在复合句中作主句的主语，引导主语从句的有从属连词that, whether以及连接代词who, what, which , whoever, whatever, whichever, 和连接副词when , where, why, ho w等。例如:
That she was chosen made us very happy.
她当选了我们很高兴。
What caused the accident is a complete mystery.
什么导致了这次事故还完全是个谜。Whoever comes to the party will receive a present.
参加聚会的每个人都将收到份礼物。
