B【精析】句意：他说他每个月把房间打扫一次。本题考查的是固定搭配的用法。have some—thing done表示“使(让，要，叫)某事被做”，强调主语意志，过去分词done表示动作由他人完成。在此表示“房间被打扫”，故B正确。
【知识拓展】put表示放置；keep可以使用为keep+宾语+宾补的形式。如:
He had his hair cut every month．他每个月理发一次。
1 will have my door repainted next week．我准备下周请人把门重新刷漆。
Where did you put the paper? 你把报纸放哪儿了?
Please keep the classroom clean and tidy．请保持教室干净整洁。
Her mother keeps her playing the piano everyday．她妈妈让她每天都弹钢琴。
Keep your mouth shut．把嘴闭上!