I sprint through beetle mania into the longhallway that bisects the second floor, down the west staircase to the first floor, grateful to be in the pre-motion-detector era.

我一路快跑冲过狂热的甲虫，经过一条长廊通向二楼，我在往西面的楼梯下去，来到一楼，我感到心情愉快，好像处在早期动作侦探时代一样。

A line that bisects a plane figure.

从中间切开一个平面图形的线。

The line connecting the point and the center bisects the included angle of the two tangent lines.

这一点和圆心的连线平分这两条切线的夹角。

A diameter is a line that bisects a circle.

直径做为一条直线把圆切成两半。

A perpendicular bisector of a chord passes through the centre and bisects the arc .

弦的垂直平分线经过圆心，并且平分弦所对的两条弧。