3.Parallel lines are, by definition, lines on the same plane that never join.
按照定义说, 平行是在同一平面上永不相交。
4.Zollner's illusion makes parallel lines seem to diverge by placing them on a zigzag-striped background.
将平行置于锯齿形条纹背上,左氏错觉会让平行看起来不平行。
5.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.