Complete the conversation with must, mustn't, have to or don't have to. have.Mother: Jane, you 1) ...must.. tidy your room while I'm out.SaraBut Mum, I want to watch TV.Mother: You can watch TV later.Sara: Do 12)wash the dishes, too?Mother: No. and you 3)wash the windows but you 4dust the furniture. Don't forget!Sara: Do you want me to water the plants?Mother: No, it rained yesterday, so you 5)water them.Sara OK, Mum. Will you bring me some chocolate?Mother. I will but you 6) mustn'tmustin't eat it all at once or you'll be sick.​

Mother: Jane, you must tidy your room while I'm out.
Sara: But Mum, I want to watch TV.
Mother: You can watch TV later.
Sara: Do I have to wash the dishes, too?
Mother: No, and you mustn't wash the windows but you have to dust the furniture. Don't forget!
Sara: Do you want me to water the plants?
Mother: No, it rained yesterday, so you don't have to water them.
Sara: OK, Mum. Will you bring me some chocolate?
Mother: I will, but you mustn't eat it all at once or you'll be sick.

Explanation:
1) "must" is used to indicate a necessity or requirement. In this case, the mother is telling Jane that it is necessary for her to tidy her room.
2) "have to" is used to indicate an obligation or requirement. In this case, Sara is asking if it is necessary for her to wash the dishes.
3) "mustn't" is used to indicate a prohibition or something that is not allowed. In this case, the mother is telling Sara that she is not allowed to wash the windows.
4) "have to" is used to indicate a requirement or obligation. In this case, the mother is telling Sara that she must dust the furniture.
5) "don't have to" is used to indicate that something is not necessary or required. In this case, the mother is telling Sara that she does not need to water the plants because it rained yesterday.
6) "mustn't" is used to indicate a prohibition or something that is not allowed. In this case, the mother is telling Sara that she is not allowed to eat all the chocolate at once.