材料：因有朋友来访未能参加昨天同事的生日会.日期：今天
问题描述：
材料：因有朋友来访未能参加昨天同事的生日会.
日期：今天
答
June 16,2009
Dear _____
i want to apologize for not coming up at your birthday party.it's just that a really good of mine came to visit me yesterday.i wanted to come to your party,but i didn't want to disappoint my old friend.i hope you would understand.
Sincerely,
__________