have to与must表达规则 — 英语选择题
题目
Mia看见一张规则卡:学生有必要戴校牌(It is necessary for students to wear ID cards.)。哪句话准确表达这条规则?A. Students have to wear ID cards. B. Students mustn’t wear ID cards. C. Students don’t have to wear ID cards. D. Students must wear no ID cards.