The fourth step: road repair and support type vehicles on the road must be turned on when signal lights.

第四步：公路抢修车及托式信号标车上路时必需开启信号灯。

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The fourth step: road repair and support type vehicles on the road must be turned on when signal lights.

第四步：公路抢修车及托式信号标车上路时必需开启信号灯。

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