answer: #Person1# teaches #Person2# how to eat steamed crabs.
documents: #Person1#: Excuse me, sir, your steamed crabs is coming. 
  #Person2#: It looks delicious. Can you tell me how to enjoy it? It's my first time to eat it. 
  #Person1#: Mix a little soya sauce, vinegar and sliced ginger on this plate and dip the meat in it before eating. 
  #Person2#: Thanks a lot.