It's always possible.

这是可能的。

普林斯顿公开课 - 国际座谈会课程节选

it's not always easy or possible

做起来没那么简单，也不太可行，

临时抱佛脚？也做过 - SpeakingMax英语口语达人

So we know we always want to have our systems in as low an energy as possible, so it makes sense that a bond would happen any time we got a lower energy when we combine two atoms, versus when we keep them separate.

我们知道我们总是希望使我们的系统,处于能量尽可能低的状态，因此就应该有化学键产生,一旦我们合并两个原子之后体系的能量变得更低，相较于分开时。

麻省理工公开课 - 化学原理课程节选

That is a very important difference that was, you had to act in such a way as to make life possible and decent, and for the Greeks that always meant being part of a decent community, the polis.

这也是个非常重要的区别,你得活出体面来,对于古希腊人而言就是,成为体面的社区即城邦的一部分

耶鲁公开课 - 古希腊历史简介课程节选