你是吴刚，是个交流学生(an exchange student), 四年前住在美国Johnson 家。现在你已经回国。根据以下要点，用英语写一篇100词左右的感谢信。开头和结尾已给出，不计入总词数。
1．感谢四年来Johnson一家人对你在生活、学习等方面的关心与帮助。
2．感悟美国家庭教育与中国家庭教育的差异(劳动态度、独立生活能力)。
3．现在正在找工作。欢迎到中国来。
注意：1. 短文中不能出现与本人相关的信息；
2. 可以适当增加细节，以使行文连贯；
3. 参考词汇：劳动态度 working attitude，独立生活能力independent living ability
Dear Mr and Mrs Johnson，
I am Wu Gang.I have been back home in China.______________ ___________
Yours truly，
Wu Gang
Dear Mr and Mrs Johnson，
I am Wu Gang. I have been back home in China. I am too eager to write a letter to you and your family the moment my feet hit the land of China. In the past four years，you have treated me like your own child，caring about my study and life. Whenever I was in trouble，you were always giving me a hand. Whenever I made progress，you were always sharing with me my joy. I am so grateful. Thank you very much.
Over the four years，I have been well aware of the differences of family education between the two countries. For example，in China，our parents tend to do everything for their children. In the USA，children are encouraged to develop working attitude and independent living ability.
Now I am making every effort to apply for a job. Welcome to China. If you come，I can act as a guide and you will enjoy yourselves.
Best wishes!
Yours Truly，
Wu Gang