at which point的用法有哪些，有何区别？

at some point  在某些时候；在某一时刻；在某一点上，通常在句中作时间状语

注意：这里的some是”某“的意思，不是很多的意思，所以后面的point不能用复数。

例如：

We're all going to die at some point .

我们都将在某个时间死去。

Each one of us is all alone at some point in our lives. 

我们的每一个人，在人生的某些时候，都是非常孤单的。

at which point 用于引导定语从句，其意为“就在这时”“就在那时”等，在许多情况下相当于 and at that (this) moment。

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

 讲演者停下来查阅他的笔记，就在这时，听到了砰的一声巨响。

注意：不能在 at which point 前加并列连词，如and.

例如：

误：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.