相反方向的

North and south are opposite directions.

北和南是方向。

I've just had an inspiration; why don't we try turning it the other way!

我突然想出一个好主意—我们为什么不试着向方向转一转呢！

A semicomplete multipartite digraph is obtained by replacing each edge of a complete multipartite graph by an arc or by a pair of two mutually opposite arcs.

摘要 用一条弧一对方向弧代替完全无向图每一条边所得到有向图被称为是半完全有向图。