而曲轴，在齿轮箱挂挡时，又使汽车持续运动。
When the gears are engaged, the crankshaft keeps the car moving.
安全开关可以是一种电子开关，当汽车挂挡后，它断开控制电路。
The safety switch can be an electrical switch that opens the control circuit if the car is in gear.
同样，安全开关也可以是机械互锁装置，当汽车挂挡后不允许点火开关转到启动位置。
It can also be a mechanical interlock device that will not let the ignition switch turn to start if the car is in the gear.
同样，安全开关也可以是机械互锁装置，当汽车挂挡后不允许点火开关转到启动位置。
It can also be a mechanical interlock device that will not let the ignition switch turn to start if the car is in the gear.
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