定语从句引导词that、which 在从句中作宾语、表语时可以省略.

I don't like this lilm,which isn't interesting at all.这是which引导的非限制性定语从句,不能省略which.
He said that he had been to Beijjing.这是that引导的宾语从句,that在从句中不担当成分,可以省略.
It is a fact that he likes watching TV.这是that引导的同位语从句,that不能省略.