He suddenly doubled and ran in the opposite direction.
他突然, 反方向跑去。
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反的方向一呢!
North and south are opposite directions.
北和南是反的方向。
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 用一条弧或一对方向反的弧代替完全多部无向图的每一条边所得到的有向图被称为是半完全多部有向图。
Double Rollers Crusher is used to crush clunch and partial shales for brick enterprises. It has two rollers to circumrotate in reverse. The clunch between rollers are crushed by extrusion.