I’m not sure whether he has the key that the door of the classroom.
A. had belonged to
B. belonging to
C. belongs to
D. is belonged to
网友回答
A. had belonged to
B. belonging to
(答案→)C. belongs to
D. is belonged to
解析：考查belong to：属于，这个词组不能用被动和进行，句意：我不确定他是否有属于教师门的钥匙。选C。