如何回复那些我不去的美国大学？

Dear Prof. XXX:

It is really my pleasure to learn that I have been offered admission to
the Graduate Program of xxx at the University of California, Berkeley. Whil
e unfortunately, I have accepted the offer of admission from Stanford Univer
sity at an earlier time. So, I am sorry to say that I have to decline the of
fer of admission from Berkeley with deep regret.
I know it may come as a disappointment to you, but it is really hard fo
r me to make a decision between these top universities. Department of XXX at
Berkeley is widely recognized as one of the most diverse and active departm
ent in the world, and I am very sorry to decline the chance to study here.
Please accept my deep appreciation for your generosity.
Sincerely yours,
XXX

告诉他们你对他们的program非常感兴趣，但一些别的因素（你选的学校
有，他们学校无）使你无法割舍，你也很痛苦，矛盾，但终于还是放弃了
他们的program。你感到遗憾，并非常感谢他们的kindness和sincere help，
你希望能有机会将来以某种方式与他们合作。

其