1."Oh, Nurse,can/may I stay here?" "Stay here? Of course, you can".2. A
man must help his parents when they become old. 3. There are no buses or
taxis, so we have to walk. 4. No, Moira you shouldn't have another potato. You've
had two already. 5. We can't/are not able to live without food and water. We must/have to eat and
drink. 6. I have to get too early tomorrow, so I shouldn't go to bed late tonight.
7. You don't need to/need not walk all the way to the station. You take a bus round the
corner. 8. Tom's father told him that he mustn't ask silly questions. 9. You shouldn't switch off the light if you are afraid of the dark. 10. The matter must/should/ought to be
discussed in tomorrow's debate.