In britain many children ( )wear uniform when they go to school

题目

In britain many children ( )wear uniform when they go to school
A.must B have to
两者选项有什么区别吗,我选A,

答案

have to表示不得不,或者客观条件要求的“必须”
must表示由于主观条件自己要“必须”
本句：在英国,当孩子上学校时,他们必须穿制服,应该是学校的规定,这属于客观条件,所以应选have to