Scientists found many stones with numbers on the mountains.
A. marking
B. marked
C. being marked
D. have been marked
网友回答
A. marking
(答案→)B. marked
C. being marked
D. have been marked
解析：考查过去分词作宾补。此题的结构为：find +宾语+ 过去分词作宾补，句意：科学家们发现在山上许多石头被刻上数字。过去分词表示被动完成，所以选B.