Fill in the blanks .Use should, have to,must, needn`t,can. 1.Nobody answers the phone.They....be out. 2.The watter was clean.You...have boiled it . 3. we...call the doctor. 4. ...you do me a favout. 5.You ... drive more carefully.
1. Must 2. Needn't 3. Should 4. Can 5. Have to