【题目】To prevent the river from __________ again, the government ordered that the factory stop running.
A. polluting B. polluted
C. having polluted D. being polluted
在线课程【答案】D
【解析】句意：为了防止河流被再次污染，政府命令那个工厂停止运营。prevent...from doing sth. 阻止……做某事，后跟动词-ing形式；因为动词pollute与the river有被动关系，故用动词-ing形式的被动式：being +过去分词，故D项正确。