at which point用于引導定語從句，其意為“就在這時”“就在那時”等，在許多情況下相當于 and at that (this) moment。如：

He lost his temper, at which point I decided to go home. 他發脾氣了，這時我就決定回家了。

The speaker paused to examine his notes, at which point a loud crash was heard. 講演者停下來查閱他的筆記，就在這時，聽到了砰的一聲巨響。

The film started to get very violent, at which point I left. 那部電影看著看著出現了極殘暴的場面，我立刻就走了。

【注意】千萬不能在 at which point 前加并列連詞。如：

講演者停下來查閱他的筆記，就在這時，聽到了砰的一聲巨響。

誤：The speaker paused to examine his notes, and at which point a loud crash was heard.

正：The speaker paused to examine his notes, at which point a loud crash was heard.

正：The speaker paused to examine his notes, and at that moment a loud crash was heard.