Dear Peter,
Thanks very much on inviting me to your birthday party on Sunday. I’d like very much e but I will had an examination on Monday morning. It is a very important exam but I can’t afford to fail it. I’ll spend all the whole weekend reading and prepare for it. So I’m really sorry that I won’t be able to e in this time. Hope you can understand. I’ll take this chance to wish you wonderful time on your birthday. Happy birthday, Peter, and many happy return of the day!
Yours,
Li Mingon-for
网友回答
(答案→)on-for
解析：
【小题1】thank you for (doing) sth.是固定用法，意思是因为……感谢你。
【小题2】这里想说我非常想去，但是我星期一早晨要参加考试，所以to-e。
【小题3】情态动词will后用动词原形。
【小题4】这里想说这是非常重要的一次考试，所以我不能失败，故but-and/also。
【小题5】the whole weekend表示整个周末，所以去掉all。
【小题6】spend (in) doing sth.是固定用法，意思是花费（时间）干某事，所以prepare-preparing。
【小题7】“这次”直接说“this time”，不用in。
【小题8】这个句子正确。
【小题9】a wonderful time是固定用法，意思是玩得愉快。
【小题10】抽象名词作主语，谓语动词用单数。