No,you can‘t .No,you shouldn’t .No,you mustn 't.这三个回答相应的问句有什

can I have dinner with you today?
no,you can't,I'm afraid.I've got a date already,sorry.
Can I pick the flower from the tree?
No,you should'nt do that.We should leave it there to let other people enjoy it.
Can I smoke?
No,you mustn't.It is a non-smoking area.
And you shouldn't smoke at all because it does you no good.