A、Eating more vegetables. B、Eating less sweet food. C、Eating food in low fat. D、Eating nutritious foods. B题干询问保持饮食均衡最重要的是什么。对话中，

M: Doctor, I am uncomfortable. I am easy to be tired. If I go up stairs, I will be out of breath. It didn’t happen before. Maybe I am seriously ill now?
W: Don’t worry. How much do you weigh?
M: About 100 kgs.
W:(12)Oh, you are overweight. You must watch your weight to keep healthy. Too fat is related to your discomfort.
M: How to lose weight? I try to do it. But every time I forget it.
W:(13)I think the best way to lose weight is doing exercises such as running, playing tennis, soccer. Besides, you can have a balanced diet.
M: What do you mean? Do you mean I must have the only meal in a day and I can’t eat meat?
W: No, it isn’t what you imagine. You needn’t do that. What you must do is to eat more vegetables than meat, and eat food high in fiber, low in fat. (14)And the most important thing is that you must eat less sweet.
M: Is sweet worst for my health?
W: Yes, I think it is. Too many sweets will make you fat, and they are also bad for your teeth.
M: It is a pity that I can’t eat delicious chocolates. What about hamburgers, French fries and Coca-Cola? I like them very much.
W:(15)Oh, they are rubbish foods. Cut down on them if you can’t cut them out.
M: I think it’s hard for me to do that. You know they are really delicious.
W: Yes, you’ll be a healthier, happier person. Remember to eat right from four food groups; dairy, fruits and vegetables, grain and meat. Those are all my suggestions for your health. If you still have questions, please ask me or call me.
M: Thanks a lot. I will do what you say.
12. What causes the man’s discomfort?
13. What is the most effective way to lose weight according to the woman?
14. What is the most important thing to have a balanced diet?
15. What does the woman suggest the man do with the rubbish food?