问题
选择题
— Mummy, I have broken my train.
一I told you so. You _______ on it.
A．mustn't have ridden
B．couldn't ride
C．shouldn't have ridden
D．needn't ride
答案
C
shouldn’t have+过去分词表示过去本不该做某事而做了。根据题意，妈妈在责备儿子本不该骑在（玩具）火车上玩。如查表示对过情况的推测，应将A改为must have ridden.