I beg your pardon,I can't attend your birthday party,really sorry,because my mother is ill,the doctor told her needs,I must stay in bed days to care for her,because she needs me,I'm really sorry!
Received your postcard,it is beautiful,is making you personally?I'll put it on the desk before every day so that we can see it!Aha...Wish you a happy birthday!
Your friend:Jim
上面加上朋友名字,下面加上日期就差不多了