And so around this time,the third,fourth,and fifth century, we get different codices,different codexes,that is books.

所以在主后第三至第五世纪，出现了各种抄本，也就是书。

耶鲁公开课 - 新约课程节选

But the time in the fourth grade maybe it's too late.

所以四年级有些晚。

麻省理工公开课 - 媒体、教育、市场课程节选

I say that a typical phalanx is eight; however, by the time you get down to the fourth century and people are doing all kinds of new and innovative things, we hear that the left wing of the Boeotian army at Leuktra was fifty men deep.

常见的方阵有八行,然而四世纪时,人们进行了一系列的革新,听说在洛伊克特拉城皮奥夏人的军队,左翼纵深五十排

耶鲁公开课 - 古希腊历史简介课程节选