Mr Wang does what he can us improve our English. A. helpB. to helpC. helpingD. helped

问题补充：

Mr Wang does what he can us improve our English.

A. help

B. to help

C. helping

D. helped

答案：

A. help

(答案→)B. to help

C. helping

D. helped

解析： 在英文中表示做某事的目的用动词不定式to do，故本题选B。