"We cannot have two administrations running foreign policy at the same time.

VOA: special.2009.01.10

You cannot have two vectors equal without exactly the same x component, exactly the same y component.

你不能说两个矢量相等,如果它们的 x 分量不完全相同,或者 y 分量不完全相同

耶鲁公开课 - 基础物理课程节选

We cannot have two 1s's sitting at the same level.

我们不能是两个1s电子同时在一个能级上。

麻省理工公开课 - 固态化学导论课程节选