—I haven’t heard from him for a long time

     —What do you think _______?

     A was happening    B to happen    C having happened    D has happened

Seeing the enemy, Gary was behaving as though nothing ______.

   A. happened            B. had happened     C. would happen       D. was happening

—We haven’t seen Jane for a long time.        
   —What do you suppose _____ to her?        
  A. was happening B. to happen     C. has happened     D. having happened 

--We haven't heard form Jane for a long time.  ---what do you suppose ___ to her?

A. was happening    B. to happen    C.has happened    D. having happened