Fill in the blanks .Use should, have to,must, needn`t,can.1.Nobody answers the phone.They....be out. 2.The watter was

1. Nobody answers the phone. They....be out. — Nobody answers the phone. They must be out.
2. The water was clean. You...have boiled it. — The water was clean. You needn’t have boiled it
3. We...call the doctor.— We have to call the doctor.
4. ...you do me a favour. — Should you do me a favour?
5. You ... drive more carefully. — You can drive more carefully.