Answers for Lesson 9: Exercise C

1. has to
Regularly repeated event, so use have to.

2. must (will have to)
This is present and future.

3. have to
Regularly repeated event, so use have to.

4. must (will have to)
This event can be understood as being in the future so we can use both forms.

5. must (will have to)
This is referring to the future.

6. must (had to, would have to)

7. had to
This is the only way to express obligation or necessity in the past. Do not use must.