What actions should you anticipate from persons at the pedestrian crossing?

The selected combination is correct because it comprehensively captures the unpredictable nature of pedestrian behavior at crossings. According to German traffic laws, drivers should always be prepared for pedestrians to display these behaviors.

1. Pedestrians might not look left or right before crossing, which emphasizes the need for vigilance from drivers.
2. The possibility of pedestrians unexpectedly walking onto the road highlights the necessity for drivers to approach pedestrian crossings cautiously.
3. The fact that pedestrians sometimes turn back halfway across indicates that drivers should be aware of any sudden changes in a pedestrian’s actions.

These points reflect the understanding that pedestrian crossings require careful observation and the readiness to react, as outlined in the Straßenverkehrs-Ordnung (StVO), which governs traffic regulations in Germany. It's essential for drivers to anticipate such actions to ensure safety for all road users.