Is this problem ___ the teacher explained last week?

问题描述:

Is this problem ___ the teacher explained last week?
A which
B that
C the one
D one
我选B老师打错!谁能讲的清楚点。
我语法不好

C.
换为陈述句看:
this problem is the one the teacher explained last week.
this problem作了explain的宾语,特指the teacher解释的问题,所以是the one.