一个英语单选题,我认为选B,可答案给的是A.请教高手到底选什么呢?

问题描述:

一个英语单选题,我认为选B,可答案给的是A.请教高手到底选什么呢?
If you had told us earlier _____ he was, we could have introduced him at the meeting.
A. who B.whom

答案A.
你想:你是谁?用英语怎么说.who are you
who 引导宾语从句.whom不可以 做表语的.
.宾语从句中引导词的用法在复合句中作主句的宾语,引导词有:
连词:that (that 常可省略),whether,if
代词:who,whose,what ,which
副词:when ,where,how,why 等.