answer: #Person2# tells #Person1# an interpreter should be an expert in everything and explains why.
documents: #Person1#: What characteristics should an interpreter own?
  #Person2#: I think he should be an expert of everything.
  #Person1#: Why is that?
  #Person2#: Because English is nothing but a tool which is used when people may negotiate in international conferences, probe into physics, release some information in a press conferrence, and do anything we can do with language. Therefore, an interpreter has to know some expertise in the field he / she serves as an interpreter. Otherwise he / she can not carry out his / her work smoothly.