Dear Tom, 

    I am really glad to hear from you. In the letter, you said you kept on studying until midnight in order to adapt to（适应） the new life in senior high school.

    Staying up late（熬夜） can do much harm to our health. If you keep on doing like this, you will get ill soon. Besides, you cannot be energetic(精力充沛的) enough to perform well at school next day. Therefore，I suggest you sleep early at night and take time to relax. Doing some exercise, talking with friends or having a good sleep can help reduce stress. When I feel stressed, I often listen to some music that can make me relaxed and refreshed（神清气爽的）.

    Best wishes!

Yours, 

Li Hua