选D 为什么? 英语题目 谢谢啦

题目

选D 为什么? 英语题目 谢谢啦
Do you still remember the key points that _ in his report? I don’t remember them all. A. referred to B. were referred C. he was referred to D were referred to

答案

Do you still remember the key points (that _ in his report)?括号内部分为定语从句,先行词为points（复数）,关系代词that代替points在定从里做主语,也就是说 the key points were referred to in his report（那些关键点在他的报告中被提到）,从句用的是被动语态