Dear Jane,
（A1 review 前情回顾）You told me in your last letter that you found yourself becoming overweight, which worried you. （A2 empahy 感同身受）I totally understand your concern because if I were you, I would feel upset as well.
（B1 situation 现状）As we know, presently, more and more students suffer from obesity because they eat too much junk food.
（B2 suggestion 建议）However, it can help you out to follow the suggestions below in order to prevent from such situation. （B2.1 建议一）On one hand, it is suggested that you should keep healthy diets so that you can stay away from too much fat. （B2.2 建议二）On the other hand, you would feel better if you could do exercise regularly.
（C wish 祝愿）I hope it helps and expect for your good news.
Yours,
Li Hua
