问题补充：
--How clean and tidy your bedroom is!
--Thanks. It every day.
A. cleans
B. cleaned
C. is cleaned
D. was cleaned
答案：
A. cleans
B. cleaned
(答案→)C. is cleaned
D. was cleaned
解析：试题分析：句意：你的卧室是多么的干净和整洁呀！谢谢，它每天都被清洁。首先必须用被动态，因为It代表房间，理应被清洁。其次应该用一般现在时，因为时间状语是every day，每天。符合要求的只有C，is cleaned。故选C。
