问题补充：
---Whose case is it?
--- I’m not quite sure. But maybe it Mr. White.
A. belongs to
B. is belonged to
C. is belonging to
D. belonged to
答案：
(答案→)A. belongs to
B. is belonged to
C. is belonging to
D. belonged to
解析：句意：上文，这个箱子是谁的？下文，我不确定。但是可能它属于怀特先生。belong to无被动语态和进行时态，表示现在的情况，用一般现在时，选A。
