I am sorry to hear that you have been ill for days and hope you have been better now. I know you learn hard and have no time for exercise, which is harmful for your health. You have been in poor health these years. I feel it would be more beneficial for you to take more exercise in the future.
You have to learn that time in exercise is not wasted. Exercise can improve your physical constitution and refresh the mind. Only when you have a strong body can you keep on studying without fatigue feeling. Otherwise your study will be interrupted from time to time by fatigue or sickness.
Of course, I am not advising you to devote all your time to exercise and I hope that you spare one or two hours to do exercise every day. Then, you will make double efforts in learning. I would be very happy to see you have a stronger body.
Dear Teacher Li,
Thank you very much for your concern. I am better now. I believe in the near future I can go back to school. Because of the illness I have a lot of homework to do. Immediately the final examination is coming, so I am very anxious. I want to go back to school and hope that the teacher can give me extra lessons. I normally do very little exercise, and the sick gave me a lesson, and then I will do more exercise later.
Dear Teacher Li,
During this period you worry about me too much. Thank you for your help and care. Thank you for arranging a good student to help me in my study, so I would't fall behind too much with others. I also recognize that a healthy body is very important to my study, so I will follow teachers' advice to do more excise. Please do not worry too much about me. I am better now, and the doctor says that I could go back to school in a week. I miss you and the classmates very much. I want to return to school as soon as possible.