题干
——I want to know if I can smoke here?
——No, you _________. Could you see the sign “NO SMOKING” there?
A：needn't
B：couldn't
C：won't
D：mustn't
答案(点此获取答案解析）
D
——I want to know if I can smoke here?
——No, you _________. Could you see the sign “NO SMOKING” there?
A：needn't
B：couldn't
C：won't
D：mustn't
2NO(g) + O2(g)，在体积不变的密闭容器中进行，达到平衡状态的标志是（ ）