参考答案
1. Dear Mr. TANG,
I beg to apply for one week's leave of absence from the 6th to 12th instant, both days inclusive, for the reason that my mother is now dangerously ill and I must return home to see her. In order to support my application, I herewith submit a copy of my mother's case report received from my family.
I should be very much obliged if you will grant me my application. As for the work to be missed during my absence, I will do my best to make them up as soon as I get back from leave.

Yours respectfully,
Yang Lihua