n.流通；循环；发行量；消息传播
The old coins have been withdrawn from circulation. 旧硬币已经收回不再流通了。
The coins were taken out of circulation. 这种硬币已停止流通。
Harvey discovered the circulation of the blood. 哈唯发现了血液循环。
This magazine has a large circulation. 这本杂志发行量很大。
These ideas have been in circulation for some time. 这些想法已经流行了一段时间。
circulation作“流通”解时,可指体内血液循环,水、空气的流通,还可指货币等的流通。指报纸杂志等的“发行量”时,常用单数形式。
n.再循环；回流；信息重记；信息重复循环
