Exercise 5: Fill in the gaps with mustn’t or don’t have to. A teacher is speaking to her students before a test: “You are going to have a test today. Your test papers are on your desks. You (1) …………………. begin until I say so. You (2) …………………. hurry; there is plenty of time. You (3) …………………. speak during the test. You (4) ………………… copy your friend’s work and you (5) …………………. open any of books. You (6) …………………. write in pen; you can write in pencil. You (7) …………………. Stay when you’ve finished; you can leave but you (8) …………………. be noisy. When you leave, you (9) …………………. Wait for your friends outside the classroom. Wait outside the building. Finally, I wish you all good luck. You can begin now!”