July 7th,2014
Dear Ms.Green,
I'm terribly sorry that I wasn't be able to attend the English class this morning. I have had a fever and Doctor suggested that I should stay in bed for a few days. Thus, I hope you will allow me to ask for a sick leave, from July 8th to July 12th. Enclosed is the medical certificate from my doctor. Looking forward to your permission!
Yours,
Lin Tao