You mustn39;t/don39;t have to open the door for a stranger. A

You mustn39;t/don39;t have to open the door for a stranger. A stranger may/should trick you. You have to/might answer the phone. You don39;t have to!may tell everybody that you are home alone . You must/might know your parents39; phone number. It must/have to be wise to know your neighbours .