I do not chew gum in public.

我不在公共场合嚼口香糖。

They are late, chew gum, talk to deskmates and have to be reprimanded and sent to the headteacher who is also a senior pupil.

他们迟到，嚼口香糖，和同桌说话，必须受到训斥，并被送到同样是高年级学生的班主任那里。

You must not chew gum in class.

你不能在课堂中嚼口香糖。

Why don't you chew gum instead?

那你为什么不嚼口香糖来代替呢？

Do not chew gum while on duty.

不要在工作时咀嚼口香糖。