I couldn't go to the theatre with you last night because I ______ babysit my Aneedn B must

问题描述:

I couldn't go to the theatre with you last night because I ______ babysit my Aneedn B must
C have to D had to

D had to 不得不
时间状语是last night ,所以动词要用过去式,只有D 符合.
句意是:我昨晚没能和你一起去剧院,因为我得照顾我的…….