【参考译文】
China was one of the world's pioneers in usingcurrency.Copper coin was the main type of currencyused in ancient China.Round coins with square holesreplaced all pre-Qin currencies and became thedominant form of Chinese currency from theunification of China in the Qin Dynasty to the end of the Qing Dynasty.However,variousmonetary systems were used throughout the dynasties.Banknote first emerged in the SongDynasty,and was widely circulated in the Yuan,Ming and Qing Dynasties.Currencies developedclosely with the social,economic and political systems in each historical period.Since the Han andTang Dynasties,Chinese copper coins and banknote began to be copied by various neighboringstates.About the same time,foreign currencies flowed into China,stimulating the developmentof an international commercial economy.
1.中国古代使用的主要货币类型是铜钱:该句的主干是“主要货币类型是铜钱”。翻译时，可把“中国古代使用的”译为过去分词短语，作后罝定语。故该句译为Cooper coin was the main type of currency used in ancient China.
2.圆形方孔的硬币取代了所有先秦钱币:其中“圆形方孔”可译为round coins with square holes,故该句整体译为Round coins with square holes replaced all pre-Qin currencies。
3.中国钱币的主要形式:其中“主要的”可用dominant表达，故该处整体译为the dominant form of Chinese currency。
4.出现:可译为emerge或appear,turn up,arise等。
5.广泛使用:即“广泛地流通”。该处翻译时应使用被动语态，译为was widely circulated。
6.大约同期:可译为About the same time。