Your bus is equipped with a ramp operated by external power or lift operated by external power. What must you check regularly?

The combination of choices you selected is correct because it addresses critical safety aspects of operating a bus equipped with a ramp or lift.

1. Checking the safety devices, such as the reversing device, ensures that the ramp or lift operates safely and does not pose a danger to passengers, pedestrians, or the driver.
2. Verifying the indicators and acoustic signals is essential for providing clear communication to those inside and outside the bus when the ramp or lift is in operation. This is crucial to prevent accidents and ensure that people know when the ramp or lift is in use.

The third option about whether the ramp or lift functions while the bus is moving is not advisable. According to German traffic regulations, ramps and lifts should only be operated when the vehicle is stationary to avoid accidents and ensure the safety of passengers.

Overall, these checks align with safety regulations that aim to protect all road users and maintain the integrity of public transportation systems.