As everyone knows, the Diaoyu Islands China since ancient times.
A. belonged to
B. were belonging to
C. have belonged to
D. were belonged to
网友回答
A. belonged to
B. were belonging to
(答案→)C. have belonged to
D. were belonged to
解析：belong 无被动语态和进行时态，故排除B和D。钓鱼岛一直是我们中国的，表示过去的某一动作或行为一直持续到现在并且将继续持续下去，故用现在完成时。