dear mr. li,
i m sorry to tell you that i m not feeling well today. i ve had a headache and a cough. i didn t sleep well last night. i went to see the doctor this morning. the doctor told me i had caught a cold, and i should stay in bed for two days. so i m afraid i can t go to school today and tomorrow. i hope i ll be all right and go back to school the day after tomorrow. thank you.