You should try your best your English.A. to improveB. improvingC. improvesD. improve

问题补充：

You should try your best your English.

A. to improve

B. improving

C. improves

D. improve

答案：

A. to improve

B. improving

(答案→)C. improves

D. improve

解析：句意：你应该尽你最大的努力提高你的英语。Try one’s best to do sth 尽某人最大的努力做某事。根据固定词组的用法。故选C。