第19题: [单项选择]______ from endless homework on weekends, the students now find their own activities, such as taking a ride together to watch the sunrise. A. Freed B. Freeing C. To free D. Having freed 参考答案:A 答案解析:[考点] 过去分词作状语
[解析] 在这里,分词短语作状语,句子主语为students,与动词free构成动宾关系,所以用free的过去分词作状语。根据题意选A。