英语定语从句练习看到的.

问题描述:

英语定语从句练习看到的.
This is the vision phone through________ we can see and talk to our friends.
填什么呢

which 原句是 we can see and talk to our friends through the vision phone.再给一题。Who is the man whom you said hello just now 这题是改错的,有人说可以在hello 加 to , 可不可以改whom为that就是在 HELLO后面加TO也可以改WHOM为THAT为什么呢?能解析一下吗?the man 是后面那句的宾语 said缺少介词 所以要加To 而这个宾语还是人 所以也可以用that