plumb-line

例句：

1. 1.The engineer used a plumb-line to measure the height of the wall.
   工程师用铅垂线测量了墙的高度。
2. 2.The construction crew used a plumb-line to level the floor.
   建筑工人用铅垂线来平整地板。
3. 3. The surveyor used a plumb-line to mark the precise location of the building's foundation.
   测量员用铅垂线标记建筑物基础的精确位置。