our goal we must try hard and do everything we can.A. AchievingB. AchieveC. To achieveD.

问题补充：

our goal, we must try hard and do everything we can.

A. Achieving

B. Achieve

C. To achieve

D. Achieved

答案：

A. Achieving

B. Achieve

(答案→)C. To achieve

D. Achieved

解析：考察不定式用法。在本句中不定式充当的是目的状语，表示为了…；句意：为了实现我们的目标，我们必须努力做找我们能做的所有事情。故C正确。