Hestayathomeandlookafterhismotheryesterday.A.neededtoB.mustC.havetoD.hasto

Question

He ________ stay at home and look after his mother yesterday.
A.needed to B.must C.have to D.has to

Answer 1

He ________ stay at home and look after his mother yesterday.
A.needed to B.must C.have to D.has to
答：此题的“正确”答案我猜是A.
分析：其实本题出得不好.首先,根据句中的时间状语yesterday可以排除CD
must 的过去式仍是must,所以AB均是正确的.但出题者可能是看到过,must改为间接引语是要改为had to之类的说法,所以以为must一定不能用于过去时态中了.
只能说：因为:1.它的形式一眼就看出（或听出）是在讲过去的事,不用听到句后的yesterday,而用must,会让人误会几秒钟,而以为是讲现在的事呢!2.我们知道,must与have to 的区别在于:must是说话者的主观看法,have to是客观上的要求.所以一般情况下,must很少用于过去的必须要做的事情的,因为说话者的观点是针对现在和未来才有意义.3.最主要的是,出题者心目中的‘正确’答案是A.