dead lever fulcrum

例句：

1. 1. The engineer used a dead lever to adjust the gears.
   工程师使用死杠杆来调整齿轮。
2. 2. The car's steering wheel is at a dead lever, making it difficult to turn.
   汽车的方向盘处于死杠杆位置，转动起来很困难。
3. 3. The scientist found the dead lever in the lab, which led to further investigation.
   科学家在实验室里找到了死杠杆，这导致了进一步的调查。