1. In my office, we __________ eat or drink at our desks. We have to go to the canteen. * 2. My job’s really nice. I __________ start work when I want and finish when I want. 3. She works from home so she _________ drive to work. * 4. Warning! Dangerous work area. Visitors _________ enter without permission. * 5. Important! You ________ keep your visitor card with you at all times. 6. He ________ travel a lot in his job. Sometimes he goes to three or four countries in a month. Điền can't/can/doesn't have to/has to/must/mustn't