Переделайте прямую речь в косвенную: 1.Mum says: “Don’t skip you breakfast. It can cause a stomachache?” 2.Dad says: “Don’t drink beer at your age. It can cause obesity.” 3. Mum says: “You should follow the diet. It can do you well.” 4.The doctor asks: “Do you have health problems?” 5..Doc says: “Eat high-fibre food more often. It will make you good.”

1) Mum says that I shouldn't skip my breakfast because it can cause a stomachache

2) Dad says that I shouldn't drink beer at my age because it can cause obesity

3) Mum said that I should follow the diet because it can do me well

4) The doctor asked if I have health health problems

5) Doctor says that I need to eat high-fibre food more often because it will make me feel good

В первых двух предложениях "shouldn't" можно заменить на "mustn't". Отталкивайся от своей школьной программы, потому что могут снизить оценку даже за такую мелочь, хотя смысл не теряется.