Bob oftenhis homework after dinner.A. doB. doesC. doingD. to do

问题补充：

Bob oftenhis homework after dinner.

A. do

B. does

C. doing

D. to do

答案：

A. do

(答案→)B. does

C. doing

D. to do

解析：句意：Bob经常在饭后做作业。分析本句中often经常体现时态为一般现在时，主语是单数第三人称，因此谓语动词用单数。故选B