A considerable amount of longitudinal play becomes apparent in the towing device of the trailer. What effect can this have?

The combination of answers 1 and 2 is correct because both of these outcomes can occur if there is considerable longitudinal play in the towing device of the trailer.

1. Damage to the cross beam of the towing vehicle can happen because excessive play can create stress and movement that the vehicle's structure is not designed to handle, leading to potential structural failure.

2. The trailer could shear off due to the instability caused by the longitudinal play, which could affect the coupling mechanism's integrity. If the connection between the trailer and the towing vehicle is compromised, it can lead to severe accidents.

Both of these scenarios emphasize the importance of maintaining a proper connection between the towing vehicle and the trailer as per German traffic regulations. Ensuring that the towing device is secure and free from excessive play is vital for safe road travel and to avoid accidents that could arise from equipment failure. It's essential to consider all relevant aspects of safety to prevent risks while towing.