Răspuns:
1. must
2.must
3.has to
4.have to
5.must
6.have to
7.had to
8.has to
9. must
10.have to
11.must
12.have to
13.must
14.has to
15.must
16.must
17.have to
18.must
19.must
20.have to
21.have to
22.must
23.have to
24.has to
25.must
26.must
27.has to
28.must
29.had to
30.have to