第5题: [单项选择]The ozone layer plays as great a role in the stability of spaceship Earth as______ the waters of its lakes, ponds, oceans, rivers, and streams. A. do B. does C. play D. are 参考答案:A 答案解析:[解析] 本题考查的是助动词+主语构成的倒装结构,强调主语,省去主要动词, waters为复数,因此A项为正确答案。