假如你是某中学某班班长李华。你们的外教老师Nancy已完成教学任务，准备回美国了。请你根据以下内容要点给Nancy写一封email，并代表全班同学对她表示感谢。内容包括：
1.代表全班向她表示感谢。
2.回顾她在同学们的英语学习上给予的帮助。
3.希望她再次来中国。
Dear Nancy,
I hear that you have finished your teaching task and will go back to America. The reason why I write to you is that on behalf of our classmates, I would extend our sincere gratitude for your kind help.
Last year you came to our school. It‘s you that have developed our interests in learning English. Your teaching methods were practical and interesting. Whats more, you sang the English songs so well and played games with us. With your help, we have made great progress in English learning, especially spoken English. Now that you will go back next Monday, all of us will miss you very much.
Thank you for your help again and give our best regards to you. We expect you can come to China again. Best wishes!
Yours,
Li Hua.
