Parallel lines are lines that never join.

行线是永不相交的线。

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

按照定义说, 行线是在同一面上永不相交的线。

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

将行线置形纹背景上，左氏错觉会行线看起来不行。

There are two parallel lines.

这有行线。

An equalarea pseudo cylindrical projection gather is constructed, in which the longitudes are hyperbola being symmetrical to the central meridian and the latitudes are parallel lines.

摘要构建了一个纬线表象为行赤道的直线，经线表象为对称中央直经线的双曲线，且面积没有变形的投影集合，并得到一组概括公式。