1. You ... never talk to strangers
A) must B) mustn't C) has to
2. as his parents went to the cinema helook after his little sister
A) has to B) have to C) must
3. Youstay here!
A) must B) mustn't
4. He return books on time
A) have to B) must C) mustn't
5. Last autumn wemove to a chaper flat
A) have to B) had to C) must
6. It is getting dark. Ito go home
A) have to B) has to C) mustn't