must/mustn't表达规则 — 英语选择题
题目
美术教室的规则是：要先拿好画纸，不能用彩笔画桌子。哪句规则写得正确？A. You must take the paper first. You must draw on the desk. B. You must take the paper first. You mustn't draw on the desk. C. You mustn't take the paper first. You must draw on the desk. D. You mustn't take the paper first. You mustn't draw on the desk.