1.duplicate用作及物动词,其基本意思是“复制”,即作一分与原件完全一致的复制品,引申可表示“复印”“重复”。
2.duplicate是及物动词,可用于被动结构。

用作及物动词
▲S+～+n./pron.
Can you duplicate the key for me?你能把这把钥匙再给我配一把吗?
The manager asks the secretary to duplicate the document.经理让秘书复印这份文件。
It occurred to us that we were merely duplicating their research.我们想到我们仅仅在重复他们的研究。
◇ 用于be ～ed结构
The document was duplicated.文件复制了。
The record-breaking harvest of 1975 may not be duplicated this year.今年不可能再获得1975年那种创纪录的丰收。
其他
All members received duplicated notices of the meetings.所有与会人员都收到了会议通知的复印件。

［词源］＜拉丁语duplicare(加倍)

Is this a duplicate or the original?这是副本,还是正本?
Your jacket's a duplicate of mine.你的夹克跟我的一样。
This form should be filled out in duplicate.这种表格要填写一式两份。