jiggering

例句：

1. 1. The engineer used a jigger to adjust the track level on the railway.
   工程师使用一个夹具来调整铁路上的轨道水平。
2. 2. The train was delayed due to the jigger operator not being able to reach the track level.
   由于夹具操作员无法到达轨道水平，火车被延误了。