假如你的朋友Mike邀请你参加他的生日Party，你因故不能参加。请你写封信向他道歉并说明情况。
内容提示：
母亲生病住院需要照顾。
买了件礼物寄去以示祝贺。
注意：字数100左右。开头和结尾已为你写好。
Dear Mike,
I am terribly sorry to tell you that I am unable to attend your birthday party next Thursday evening. That is owing to the fact that
Yours
Li Hua