Choose the correct answer. 1) Drivers speak on the phone while driving. a) couldn't b) mustn't c) need not 2) I ask you some questions about your life? a) should b) must c) could 3) see a dentist, I have a toothache. a) ought to b) can c) might 4) Drinking a lot of alcohol. cause addiction. a) must b) couldn't c) can play with his brother than going out. b) may c) had better 5) He a) need not