Dear Miss Wang
I would like to say"Thank you" most at he moment.I can never pay you back for you kindness and your patience.I used to be lazy to learn English and too shy to speak English English in front of the class.You found my problem and helped me out.With your help I made great progress and became the top student in our class.It was you who gave me a hand when I was in difficulties.
Yours
Li Ping