midpoint tap

例句：

1. 1. The engineer used amidpoint tap to mark the center ofthe circle.
   工程师用中点敲击标记圆的中心。
2. 2. During the construction, the workers usedmidpoint taps to ensure the properplacement of the beams.
   在施工过程中，工人们使用中点敲击器确保梁的适当放置。
3. 3. The midpoint tap was used asa tool for measuring the distancebetween two points on the map.
   中点敲击器被用作测量地图上两点之间的距离的工具。