Obligation
Fill in: must-have to-should/ought to
9. The buses were all full; I take a taxi.
10. You (not take ) my keys, Why did you take them?
11. We be there not later than August, 10.
12. When a tyre is punctured the driver change the wheel.
13. We go there at once.
9. must
10.didn't take
11.should
12.should
13.must