1--Thank you very much for everything you have done for me during my stay in China.
 
2--And I must thank you again for your generous help.
 
1--The help is mutual. I must thank you to see me off. My wife and I will be looking forward to seeing you.You will come to see us won't you?
 
2--l promise I will take the first chance to call on you. Please send your wife with my best regards.
 
===================================
注解：
 
1.during在…期间    
2.generous慷慨的
3.look forward to盼望  
 
===================================
译文：
 
1--十分感谢我在中国期间您为我做的一切。
2--我必须再次感谢您的慷慨相助。
1--帮助是相互的。谢谢你为我送行。我和我的妻子盼望着和您见面。你会来看我们，是吗？
2--我答应一有机会马上去拜访您。请代我向您的妻子问好。