33. --Were you at home at 7:00 yesterday evening? I called you but no one was there.
   --Sorry, we ___________ a movie at the theatre at that time. 
A. watch            B. were watching    C. watched        D. are watching
34. The boy often ________ his homework at school.
 A. leave    B. leaves    C. forget    D. forgets
35.  --Mark, you look so tired.
   --Oh, I didn’t go to bed _______it was 12 o’clock last night
   A. before         B. after           C. until          D. when
36. You can find ___ difficult t o learn English.