Complete the sentences with must or mustn't. 1. hurry up, james-we be late. 2. i remember to phone sonia tonight. 3. here's your present. you open it before your birthday! 4. you forget to lock the door before you leave. 5. if you go to london, you go to the trocadero-it's great! 7. vy old dictionary is useless - i buy a new one.