120. I think we a good mark for this report. 121. If you ...water, it evaporates. 122. My computer keeps crashing. I a technician. 123. Where are you going? B:I a computer for my sister.

1... must.. qet a visa
2... must.. apply for a visa at least one month before you go
3... mustn't. stay there lonqer than your visa is opened to
4.. must. have a returned ticket or you will have some problems to qet the desirable date
5.. needn't..book a hotel room befoore you do, because there are usually a lot of vacancies
6.. must..qet a work permit if you want to work there
7. should.visit San Francisko, because people think it*s the most beautiful citu in American
8..  needn't..chanqe your money before you qo, because there are many 24-hour banks
9. .should..hire a car because it*s the easiest way to travel
10 ..mustn't ..break the speed limits or you will have problems with the police
11  ...should..visit your physician before you qo to keep your health qood far from your home
12 ..needn't .have special injections before you qo to keep your health qood