非限制性定语从句的连接词不能单独省略,本句是同时省略连接词和系动词.再如,He passed all the exams this term,which made his parents very happy.也可以这样表达,He passed all the exams,making his parents very happy.再比如,He saw a reference book in the bookshop,(which was ) the very book that he wanted.