axis of rotation

例句：

1. 1.The car's steering wheel is on the left side of the vehicle.
   汽车的方向盘在车辆的左侧。
2. 2. The machine rotates the gears to change speeds.
   这台机器通过旋转齿轮来改变速度。
3. 3. The axis of rotation is perpendicular to the plane of rotation.
   旋转轴与旋转平面垂直。