努力学习，不然你就会落后时代。

Work hard, or you will fall behind The Times.

youdao

肇基于生产力水平和科技文化极端落后时代的中华文明，不可避免地带有早熟性。

The Chinese civilization based on the extremely unenlightened level of productivity, science and culture inevitably bears the character of being precocial.

youdao

我们倾向于认为生活在那个时代的人一定很落后。

We tend to think that people who lived at that time must have been pretty primitive.

youdao

Although the political development came late in the process, it did come.

尽管政治体制的发展落后于时代的潮流,但终究有一天它还是来临了

耶鲁公开课 - 古希腊历史简介课程节选

so I'm behind times on that.

所以我在这方面有点落后于时代了。

现在的孩子好可怕 - SpeakingMax英语口语达人