Tom__look after his mother.She has been ill these days A.have to B.has to C.had to D.will have to

题目

Tom__look after his mother.She has been ill these days A.have to B.has to C.had to D.will have to

答案

选B.
Tom是第三人称单数,所以选择has to（不得不）.此句句意：Tom不得不照顾他的妈妈,（因为）她的妈妈（这几天）病了.