【题目】_______ the classroom for a whole afternoon, the monitor decided to have a rest.
A. Having cleaned B. To clean
C. Cleaned D. Clean
在线课程【答案】A
【解析】考查非谓语动词。句意：整个下午打扫了教室之后，班长决定休息一下。句中clean的动作比decided早，故用完成时；the monitor和clean是主动关系，此处作状语用动词-ing形式，故此处用动词-ing形式的完成时，故选A。