时间表述单位:宙、代、纪、世、期。地质年代中各个宙、代、纪、世、期或时都有自己的名称,用于描述生物在不同地质时空的发展程度, 。
time of Time units are eon, era, period, epoch, stage. eon. Every eon, era, period, epoch, stage, chron has its own name to describe the development degree of organisms in different geological tim…