leadline

例句：

1. 1. The engineer used a leadline to measure the distance between two points.
   工程师使用铅垂线测量两点之间的距离。
2. 2.The painter carefully drew a leadline onthe canvas.
   画家小心地在画布上画了一条铅垂线。
3. 3. The constructionworkers used a leadline to mark thefoundation of the building.
   建筑工人使用铅垂线标记建筑物的基础。