The poor employee , made ________ several hours of hard work every day , couldn’t stand his employer any longer , leaving without a word．

1. A.
   do
2. B.
   doing
3. C.
   to do
4. D.
   done

The poor employee, made_____several hours of hard work every day, couldn’t stand his employer any longer, leaving without a word.

　 A. do　　　　　　　 B.doing　　　　　 C.to do　　　　 D. done