I know it's possible to induce chemical reactions, but these are exceptions. This is not the norm.

我知道催化化学反应是可能的，但是那些是特例，不是常规情况。

麻省理工公开课 - 固态化学导论课程节选

So, remember, boron was one of those exceptions to our Lewis structure rules where it was perfectly happy not having a full octet.

所以我们可以加上3个氢原子,对于BH3，这是个稳定结构,记住，B是Lewis结构的一个特例。

麻省理工公开课 - 化学原理课程节选

The question when we see exceptions, whether it's the Lykken and Tellegen study, not all twins were the same, the question is no longer whether or not change is possible, but rather how is change possible.

当我们看到了例外，无论是在Lykken和Tellegen的研究，当发现不是所有的双胞胎都一样，已不再是，改变是否有可能，而是怎样实现这种改变。

哈佛公开课 - 幸福课课程节选