Take any two points on any plane and draw two rays in the same direction. Let the starting endpoints of the two rays be x and y respectively. When ray x and ray y are at length z and z is not equal to 0, it is "puberty". It is known that ray x and ray y can be infinitely extended in the same direction. How many possibilities are there for ray x and ray y to intersect or not intersect?
Concept: So what is regret? The shiver of memory? Or the collapse of sadness...