Ex. 1. We can finish this today.
This can be finished by us today.
2. They may keep it for two weeks.
3. You can pay the bill later.
4. We have to deliver it tomorrow.
5. They can’t put those things there.
6. They must send it at once.
7. They should deliver it today.
8. John must study these exercises.
9. They may bring it later.
10. You can use this room for your lesson.