iron period的意思|示意

It would become trapped inside for a long period of time, reacting with iron, calcium, and sea water in the rocks to make chalk (known more technically as carbonates).

液化二氧化碳将会在岩石中贮存很长的时间，与铁、钙以及海水产生化学反应产生白垩(即术语所说的碳酸盐)。

The planet orbiting Kepler 10, by contrast, has an orbital period of a mere 20 hours and is so dense that it is probably made of iron.

相比之下在开普勒-10轨道中发现的那颗行星其轨道周长只有20小时，而且密度很高以至于研究员估计行星内部是由铁组成的。

During the Spring and Autumn Period, the agricultural production was highly subject to the seasonal changes with the invention of iron tools, thus forming the concept of Solar Term.

春秋战国以后随着铁制农具的出现，农业生产对季节性的要求更高了，就逐渐形成了节气的概念。