[解析]
Dear Black,
I am writing to express my thanks for your kind help during my visit in England. Many thanks for all the things you have done for us. And thank you for the gift you sent me. It's one of the best gifts I have ever got.【高分句型一】(感谢帮助)
During my stay in your country, you offered us such good opportunities to communicate with you and your students. Therefore, I have learned more about English culture and my English has improved a lot. Besides, I have made several good friends there.(交流感受)
I am looking forward to your early visit to China so that I will show you around our country.【高分句型二】Thank you again for your kind help.(欢迎来访)
Yours sincerely,
Li Hua