Поставьте в пропуски must, mustn039;t, have to, don039;t have to, can

Поставьте в пропуски must, mustn't, have to, don't have to, can or can't
1) A:Do we ......finish this exercise in class?
B: No, you..... . You ..... finish it at home if you like - but you ..... finish it before the next lesson!
2)A: I hate waitingfor the bus in the morning!
B: Fortunately, I ...... take the bus, because I go to school by bike.
3) A: You ..... help me with the washing-up if you're busy, you know
B:No, I'm happy to help- but I...... forget to write my report for tomorrow
4) A:I'm afraid I..... go out with you tonight - I ...... visit my parents
B: ...... I come with you,then?