dì / zhì / xué / kè / chéng / jiè / shào / le / yǐn / shēng / zhòu / zhè / yī / gǔ / lǎo / de / dì / zhì / nián / dài

地质学课程介绍了隐生宙这一古老的地质年代。

The geology course introduced the ancient geological eon known as the Cryptozoic.