—What  do you think of Sam, the newcomer?
 —Well, he talks as if he ________ everything. 
       A. had known     B. has  known        C.  knew        D. will know
 
 —What  do you think of Sam, the newcomer?
 —Well, he talks as if he ________ everything. 
       A. had known     B. has  known        C.  knew        D. will know
 
 C