mirror extensimeter

例句：

1. 1. The mirror extensimeter is used to measure the distance between two points on a surface.
   镜子延伸计用于测量两个表面点之间的距离。
2. 2. The engineer used the mirror extensimeter to check the accuracy of the measurements.
   工程师使用镜子延伸计来检查测量的准确性。
3. 3. The mirror extensimeter was used to determine the dimensions of the new building.
   镜子延伸计被用来确定新建筑的尺寸。