No student go out of school for snacks during the break without the teacher’s permission.A

问题补充：

No student go out of school for snacks during the break without the teacher’s permission.

A. shall

B. must

C. will

D. may

答案：

(答案→)A. shall

B. must

C. will

D. may

解析：句意：没有老师的允许，没有学生在课间可以出学校买零食。这里用shall，用于第二人称或第三人称表示“警告，允诺，命令，规定”，must必须，will愿意，may可以，根据句意选A。