Bricklayers and carpenters often use plumb lines . 瓦工和木工经常使用铅垂线。
2.
Absolute orientation of aerial imagery over urban areas combined with vertical lines 铅垂线辅助城区航空影像的绝对定向
3.
Its mast can be installed in inclination according to the requirement of construction the angle between the axis of mast and vertical line should be 10 , while the floor of cage always remains level 该系列升降机无对重，导架按施工需要而倾斜安装导架轴线与铅垂线夹角10 ，但吊笼地板始终与水平面平行。
