answer: Wang Peng calls Mr. Smith to thank him for the wonderful dinner yesterday and his help during Wang Peng's stay.
documents: #Person1#: Hello, Mr. Smith, Wang Peng speaks.
  #Person2#: Hello! Mr. Wang. this is Smith.
  #Person1#: I'm calling to thank you for the wonderful dinner I had yesterday.
  #Person2#: It's a pleasure.
  #Person1#: I'll come back to China tonight. I hope to see you again sometime.
  #Person2#: I hope so.
  #Person1#: I appreciate all help of you during my stay here.
  #Person2#: Don't mention it.
  #Person1#: Please let me know when you go to China and let me be of some assistance to you.
  #Person2#: Yes, I will. Have a nice flight back.
  #Person1#: Thanks, good-bye!
  #Person2#: Good-bye!