----look,Ann is on the playground over there.----- It______be her,because shi is still in hospital

问题描述:

----look,Ann is on the playground over there.----- It______be her,because shi is still in hospital
A.may be B.mustn't C.should D.can't

根据后面那人的话:...because she is still in hospital 可以看出这是一个语气肯定的否定猜测句,must be 用于语气肯定的肯定句中,用在否定句中时应为can't be,选D.(其他的选项may be ,should be 的语气不够肯定).
满意的话就给我分吧^-^.