Fill in with the correct form of mustn039;t,don039;t need to/don039;t have

Fill in with the correct form of mustn't,don't need to/don't have to.
1)You ....... get stressed about the homework-it's easy.
2)You.......eat too much junk food-it's bad for your health.
3)She......change her diet-she always eats healthy food.
4)The children.....watch too much TV-it's bad for their eyes.