Dear Ms Ma,
敬愛的馬老師：
I apologize that I cannot go to school today.
很抱歉我今天不能去上學了。
Last night my mother had a high fever and coughed badly. I think that she has got flu.
昨天夜裡我媽媽發高燒，咳嗽得厲害，我想她可能是得了流感。
She didn't have a good sleep and is very weak today, so I will go to Tiantan Hospital with my mother, and then stay at home to attend her.
昨天晚上她休息得不好，而且今天很虛弱，所以我陪媽媽去天壇醫院，然後在家照顧她。
Because of this I have to ask for leave.
因此我不得不請假。
I will appreciate you very much if you can allow my leave.
如果您能准假我會非常感激。
Yours, Li Li
您的學生 李麗