This big bag is too heavy for the little boy .Who volunteers to help him?A. carries B. car

问题补充：

This big bag is too heavy for the little boy .Who volunteers to help him?

A. carries

B. carrying

C. carried

D. to carry

答案：

A. carries

B. carrying

C. carried

(答案→)D. to carry

解析：句意：携带这个大包裹对于这个小男孩来说太重。谁自愿帮助他一下？句式It is adj for sb to do sth中不定式做补足语，表示具体的动作。故选D。