Every day we should keep our classroom .A. cleaningB. to cleanC. cleanD. cleans

问题补充：

Every day we should keep our classroom .

A. cleaning

B. to clean

C. clean

D. cleans

答案：

A. cleaning

B. to clean

(答案→)C. clean

D. cleans

解析：句意：每天我应该保持我教室干净整洁。Clean可用作动词和形容词，本句中clean用作形容词，干净的，作宾语补足语。如果用作动词，则缺少逻辑宾语，语义不通，故选C。