求一篇英语作文

Dear Mary,
How are you.
I'm writing this letter to express my heartfelt appreciation of what you have done for me over the past semester. As a friend online, you have not only helped me a lot in improving my English skills, but also had many candid discussions with me about my future plan for career development. To tell you the truth, I feel so encouraged by our online chatting that I now have full confidence in my success after graduation.
I'm really lucky to bump into a good and true friend like you in the virtual world of the Internet. I hope we can keep this beautiful friendship for a lifetime. And in the future, if you need any kind of help from me, just tell me. I promise I will do my best to assist you, just as you did for me.
Keep in touch. Wish you every success in life and career!

Yours sincerely,

Li Hua