of the heavy burden of homework, the children rushed out of the classroom and enjoyed themselves.
A. To be free
B. Freeing
C. To free
D. Freed
网友回答
A. To be free
B. Freeing
C. To free
(答案→)D. Freed
解析：这题考查过去分词做状语的用法，free sb of“使某人摆脱”，the children和free之间是被动关系，句意是：摆脱了作业的负担，孩子冲出教室玩得很愉快。选D。