Miss Chen,
I'm appreciated that you have taught me for such a long time.Because of your patient teaching,I have a great improvement in my English subject.Now due to the new year's achieving,I believe it' high time for me to say to you,"happy new year!."
yours,
xxxxxx
这个是英语的,汉语的你自己可以随便就写出来了吧~呵呵