Dear Jane,

Lately, you feel bad about your physical condition. You inquired about how to develop fitness from me. Thus, I give advice for you (改：give you some advice) .（段评：本段作为书信正文开头,清晰说明了写作目的,很棒！但有两处需要改进: 1. 时态误用:'you feel bad'应改为'you've been feeling bad',用现在完成进行时更能体现持续的状态；'I give advice'应改为'I'd like to give you some advice',用委婉表达更符合书信语气。 2. 介词搭配:'give advice for you'应改为'give you some advice'或'give advice to you',这是固定搭配。修改版：Lately,you've been feeling bad about your physical condition. You asked me how to get fit,so I'd like to give you some advice.）

Firstly, you should keep an appropriate diet, such as declining (改：cutting down on) junk food and eating more fresh vegetables and fruits. Secondly, you should do jogging or other sports. Then, you should also keep enough sleeping (改：get enough sleep) and don't stay up late. You must consult a doctor if you still feel bad.（段评：本段建议具体,条理清晰！但有几处可以优化: 1. 词汇搭配:'declining junk food'应改为'cutting down on junk food','decline'更侧重婉拒邀请,'cut down on'才是减少摄入的正确表达；'keep enough sleeping'应改为'get enough sleep',这是固定搭配。 2. 逻辑连接:添加'Finally'使建议的层次更分明；'You must consult'改为'It's better to consult'语气更委婉。修改版：Firstly,you should keep a balanced diet,such as cutting down on junk food and eating more fresh vegetables and fruits. Secondly,you should go jogging or do other sports regularly. Finally,you need to get enough sleep and not stay up late. If you still feel unwell,it's better to consult a doctor.）

You should memorize (改：remember) that health is the biggest welfare.（段评：本段点明主旨,很好！'memorize'应改为'remember','memorize'更侧重背诵,'remember'才是记住的正确表达；'welfare'应改为'wealth','health is the greatest wealth'是更地道的表达。修改版：Remember that health is the greatest wealth.）

Yours,

Li Hua