Paper cutting are used to decorate doors. 是主谓宾还是主系表?
Paper cutting (主语)are used (谓语)to decorate doors (宾补) 是主谓宾结构,主系表的结构是:主语+系动词+表语。一些过去分词可以转换成形容词作表语,表示状态。如; The cup is broken. He is excited. They are frightened.