1.must
2.have to
3.must
4.mustn't
5.have to
6.have to
7.have to
8.must
9.don't have to
10.musn't
11.must
12have to
1.must
2.have to
3.must
4.mustn't
5.have to
6.have to
7.have to
8.must
9.don't have to
10.musn't
11.must
12have to