Dear Mr Chen,
I'm sorry to tell you that I can't go to school today. I've caught a cold because I swam in the Kunming Lake yesterday.
This morning I had a headache. After taking my temperature, my mother found that I had a high fever. She took me to see a doctor. The doctor advised me to stay in bed for two days.
Now I'm writing to you to ask for two days' sick leave.
写请假条要注意写清请假原因和时间。请假理由一定要写充分。如果是请病假最好附上医生证明。 Eng lishtang.com