answer: #Person2# thinks an interpreter should be an expert of everything and explains #Person2#'s reasons.
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.