高中英语道歉信如何写？( 八 )

很抱歉，上星期您借给我的那本书竟遗失了。我每天都在看，准备下个月看完。昨晚我回到我的卧室，到处也找不到那本书。我将尽力找到它。万一找不到，我只好买一本新的还您。
但是，新书恐怕不能代替那本旧书吧！旧书跟旧友一样，一旦失去就不能再得。旧书与往事相连，这种不可弥补的损失，皆由我起。我对待一切太大意了，这次给我一个警告，叫我以后要小心。
dear sarah,
i am terribly sorry to tell you that i am unable to attend your birthday part next thursday evening. that is owing to the fact that my younger brother suddenly fell ill and was taken to a hospital this morning. i have to go there immediately and take care of him. as told by the doctor in charge, it will take around five days for him to recover and i have asked my boss for a leave.
i really regret that
i cannot go to celebrate your birthday personally and would miss the perfect chance of enjoying myself with all our old friends. i have chosen a small gift for you and will send it to you tomorrow to show my best wishes. besides, please give my regards to our friends when you meet them at the party. cordially,
li ming