Point作为先行词， 后面接定语从句。下面举例说明:
We are just trying to reach a point where both sides will sit down together and talk.
句意: 我们正在试图找到双方能坐到一起谈判的点。
Point作为先行词， 表示抽象的时间点和地点， 在定语从句中充当地点状语，所以用where引导。
After graduation she reached a point in her career where she needed to decide what to do.
Point作为先行词， 仍然表示抽象的地点。定语从句用where做引导词。
We have got to the point where a change is needed.
Point作为先行词，表示抽象地点。定语从句用where作引导词。
He has got himself into dangerous point where he is likely to lose control over the plane.
他使自己陷入了一种危险的境地，在这种情形下，他可能失去对飞机的控制。
