那些更容易感染疾病和寄生虫的男性将不得不使用他们的类胡萝卜素来增强他们的免疫系统。

Males that are more susceptible to disease and parasites will have to use their carotenoids to boost their immune systems.

youdao

但是，不可回避的事实是煤这样的化石燃料深深扎根我们的能源体系，我们将不得不使用他们很多年。

But the unavoidable reality is that fossil fuels like coal are deeply embedded in our energy system, and we'll have to use them for years.

youdao

And I think many parents believe that if they didn't persist in using these things their children would never learn to speak.

我相信很多父母认为,如果他们不坚持使用这些东西,他们的孩子将永远也学不会说话

耶鲁公开课 - 心理学导论课程节选