版上各位大神好!
小弟刚刚读新英看到一段如下
The man struggled to escape the tigger's grasp with help from his friend,
“at which point” a zoo employee heard screams and came to their assistance.
小弟的疑问在于这个 at which point 是如何化简来的?
感觉at which 感觉是关系副词，可是如果是这样也不会放在先行词point前面
还是是这样子变过来的 at the point at which ... (自己乱猜测...
还是其实只是个固定用法? 囧
感谢大神解惑!

原本at that point因为没连接词=> at which point

以前碰到这个用法时我问外国朋友他们是说可以当成and at the moment来理解就跟一楼讲的一样，后一句照正常写法应该是会写成a zoo employee heard screams......at that point.要把两句接起来的话，或者用对等连接词(and)或者将at which point当作关系词，然后前半句的整句话发生的那个"point"就变成at which point的先行词了

非常清楚感谢两位大大!