horizontal spacing between purlins

例句：

1. 1.The car was parked horizontally on the street.
   汽车停在街道上，横向停放。
2. 2. The painting is painted in a horizontal stroke.
   这幅画是用横向的笔触绘制的。
3. 3.The bookshelf is arranged horizontally.
   书架是横向排列的。