2. Mary may / might/ try to call us.
3. The students have to / must / finish the test in one hour.
4. Mum must / may / be working in the garden.
5. Rachel must be hungry.
6. Dad may /might / take us out to dinner.
7. Lucy couldn't reach the situation yet.
8. Grandma have to /must / take her medication every morning
9. They must / might / have gone to the supermarket.
10. Bob couldn't leave the party early.
ex III
2. must /have to /
3. must / have to
4. mustn't
5. needn't / don't have to /
6. mustn't / needn't /