【正确答案】Dear Zhang Ailing,
I am writing the letter for the purpose of conveying my heartfelt congratulations on your admission to Nankai University.
I know how hard you have worked to achieve this goal. Therefore, I can imagine your excitement when you realized such an ambition. Indeed, no one could have been more deserving than you. On the other hand, for me, it is a real encouragement to see your efforts rewarded. In short, I take pride in your present success.
Please accept my heartfelt congratulations. Wish you still further success.
Yours truly,
Zhang Wei

【答案解析】首段只有一句，表明写作目的——祝贺对方被大学录取。第二段共五句。首句讲述对方付出的艰辛和努力。第二句和第一句是因果关系，用了连词therefore，表明对方的喜悦之情可以理解。第三句评价对方的成功是应得的。第四句表明自己也深受激励。第五旬总结自己以对方为荣。第三段共两句。首句请对方接受自己的衷心祝贺，使用了一个形容词heartfelt，意思是“衷心的”。第二句祝愿对方以后获得更大的成功，是祝贺信的经典结尾句型。