Ex1
1 b
2 a
3 b
4 a
5 a
6 b
Ex2
1 mustn't
2 must
3 don't have to
4 has to
5 must
6 have to
7 don't have to
8 had to
9 have
10 mustn't
Ex1
1 b
2 a
3 b
4 a
5 a
6 b
Ex2
1 mustn't
2 must
3 don't have to
4 has to
5 must
6 have to
7 don't have to
8 had to
9 have
10 mustn't