平行线

Zollner's illusion makes parallel lines seem to diverge by placing them on a zigzag-striped background.

将行线置于锯齿形条纹背景，左氏错觉会让行线看起来行。

Parallel lines are lines that never join.

行线是永的线。

There are two parallel lines.

这有两条行线。

Parallel lines are, by definition, lines on the same plane that never join.

按定义说, 行线是在同一永的线。

Graph paper, parallel, and planimeter methods are current tools for acreage calculation.

目前常用的量算积方法有方格纸法、行线法、求积仪法。