time-space trade-off

Kennedy mischievously suggested that professors ought to trade jobs for a time with janitors…

肯尼迪调皮地建议教授和看门人互换一段时间工作。

While human achievements in mathematics continue to reach new levels of complexity, many of us who aren't mathematicians at heart ( or engineers by trade) may struggle to remember the last time we used calculus.

虽然人类数学成就的复杂性持续再创新高，但我们当中许多本身并非数学家(或者职业并非工程师）的人，可能很难记住我们最后一次使用微积分是什么时候了。

Kennedy mischievously suggested that professors ought to trade jobs for a time with janitors

肯尼迪调皮地建议教授和看门人互换一段时间工作。

By the time the Chinese silk trade became important in the world.

到了中国丝绸贸易在世界上变得重要的时候。

They judged that the time was right for the proposal of new terms for the trade agreement.

他们判断，提出贸易协定新条款的时机成熟了。