Our classroom by us every day!A. is cleaningB. has cleanedC. must cleanD. is cleaned

问题补充：

Our classroom by us every day!

A. is cleaning

B. has cleaned

C. must clean

D. is cleaned

答案：

A. is cleaning

B. has cleaned

C. must clean

(答案→)D. is cleaned

解析：句意：我们的教室每天被打扫。本句主语是classroom且时间为every day，故使用一般现在时被动语态。