Choose two points from eight vertices and connect them with straight lines, and you will get C2, 8=28, where any two points are C2, 28=378.

There are eight straight lines perpendicular to an edge, and the total number of edges is *** 12, which means 12*8=96.

One diagonal, two straight lines perpendicular to it, 12 diagonal lines, that is, 12*2=24.

So there are 96+24= 120 vertical straight lines.

So 120/378=20/63. I don't know if it's right.