From the dates on the gold coin, we decided that it was made five hundred years ago.
A. marking
B. marked
C. to be marked
D. having been marked
网友回答
A. marking
(答案→)B. marked
C. to be marked
D. having been marked
解析：本题是定语从句的省略。可以将原句恢复成“From the dates(which were) marked on the gold coin'’，这样就比较容易找出答案。