一.   选择题

(   )1. I often hear Mary ________ in her room.

     A. sing       B. singing      C. to sing      D. sang

(   )2. They knocked him down and _________ him of this bag.

     A. rob       B. robbed       C. steal        D. stole

(   )3. He has difficulty with his English, ________, he works hard and is making great progress.

     A. and       B. but         C. however      D. yet

(   )4. Sally doesn’t have to be made ________. She always works hard.

     A. learn      B. to learn      C. learned      D. learning

(   )5. They _______ carefully, but ______ nothing.