我已经很久没教过这门课了，所以我怀疑你在大学阶段可能没有学过关于那个时期的内容。

And I haven't offered it in quite a while now, so I doubt you ever studied that period on the college level.

youdao

在美国，交通运输业生产率大幅提高的时期可能即将结束，但在大多数国家，这一阶段仍有很长的路要走。

In America, the period of huge productivity gains in transportation may be almost over, but in most countries the process still has far to go.

youdao

研究主要表明，人在40多岁或50多岁时可能会有个停滞时期，或转变阶段，但是这种转变“会让人感到兴奋而非恐惧”。

The bulk of the research shows that there may be a pause, or a shifting of gears in the 40s or 50s, but this shift "can be exciting, rather than terrifying".

youdao

Example, protein hormones are insulin which we've talked about before and glucagon, and growth hormone which we haven't talked about but that's very important during periods of life like adolescence, when rapid growth of your bones is occurring.

例如,我们以前讲过的胰岛素,还有胰高血糖素都是蛋白质激素,生长激素也是,尽管我们还没有讲过它,但它在人的青春期阶段,起着非常重要的作用,骨骼在此时期快速生长

耶鲁公开课 - 生物医学工程探索课程节选