有什么信息补充吗同学？没有的话我写的这个版本应该符合你的需要。
Dear B:
Hello!
Haven't heard from you for so long! Is everything goes on well with you? I am Li, your Chinese friend and schoolmate who had been studied with you in America for half a year. Although we haven't seen each other since I left, I still appreciate your help and kindness to me. I miss you so much that I would like to invite you to come to China and experience our culture. I am sure you will be impress by our great eastern civilization. By the way, can you tell me the way to contact our teacher in America? I fail to get in touch with him because I lost his contact information.
Best wishes,
Sincerely,
Hua Li