参考答案

正确答案：D
解析：独立主格结构题。此句的完整句式是：The little boy came into the room after playing football for 2 hours and his face dripped with sweat．省略连词and，然后根据后句的主语和谓语是主动的关系，把谓语动词drip的过去时变成现在分词dripping就把后半句话变成了独立主格结构。