Dear Mrs.XXX,
Thank you for your teaching! I hope you will have a wonderful time!you are tired in the past year.i hope eveything goes well ! and i am grateful for your teaching me,i will reciprocate you when i grow up and make success!
yours
**

敬爱的X老师:
感谢您的教育!我希望你能有个快乐时光!过去的一年您辛苦了,我希望您万事如意!真的很感激您对我的教育,在我长大成功之日一定会来报答您对我的关爱.
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Hi,
I just want to say thank you for your visit while I was sick and tell you how much I appreciate it. It really made me feel a lot better. It was a great joy for me that you came. And thanks again.

Hi,
我想为你在我生病时来看我而感谢你,并告诉你我有多么欣赏你的行为(英语里常用的感谢词).你来的时候我很高兴,看到你也让我感觉好了很多.再次谢谢你.
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Dear Sir,

How are you?

I was told that you decided to support me for my further study. I was so excited and deelply appreciated that you can help me. My parents also appreciate your finacial support so that I don't need to worry about discontinuing my study. I will try my best to study as hard as I can and my outstanding achievement will be my best return for your help.

Currently, there's a very big global financial crisis happend, including United States. I hope that you didn't get any bad impact from it.

Kindest Regards and all the best to you,

Yours +(name)