must/mustn't表达规则 — 英语选择题
题目
学校有两条规则：走廊里不能跑；纸要扔进垃圾桶。哪组英文规则正确？A. You must run in the hall. You must put paper in the bin. B. You mustn't run in the hall. You must put paper in the bin. C. You mustn't run in the hall. You mustn't put paper in the bin. D. You must run in the hall. You mustn't put paper in the bin.