从句省略一般分三种
动词+ED省略
当从句是被动语态的时候，关系代词和be动词一般可省略。
原句： She only eats cake that are made by their mother.
简化： She only eats cake made by her monther.
原句： This vase, which was made in china in the 14th century , is very valuable.
简化： This vase ,made in china in the 14th century , is very valuable.
动词+ING省略
当从句是主动的时候，关系动词和be动词一般可省略。
原句： The Bond fans, who are waiting outside want their books signed.
简化： The Bond fans, waiting outside want their books singed.
原句： The new book , which is coming out in may , is about James Bond.
简化： The new book , coming out in may , is about James bond.
Being + 动词ing
被动进行时态的从句， 关系动词和Be动词一般可以省略。
原句： The strawberries that are being eaten at the wedden were grown in scotloand.
简化： The strawberries being eaten at the wendding were grown n scotland.
