secondary era

• 中生代

secondary era的用法和样例：

例句

1. Mammals arose from a fairly primitive reptile in the Mesozoic era.
   哺乳类起源于中生代宛若原始的爬虫类。
2. Anning Basin is a terringenous fault basin developed in Mesozoic Era.
   云南安宁盆地为中生代陆相断陷盆地。