In which cases should you apply the brakes only very carefully?

Your answer was correct, as it identified all the scenarios where careful braking is essential according to German traffic rules.

1. On roadways with loose chippings or sand, applying brakes too hard can cause loss of traction and increase stopping distance, leading to potential skidding.
2. When encountering tram tracks, sewer covers, and lane markings, their smooth surfaces can cause the vehicle to slide if brakes are applied suddenly, especially in wet conditions.
3. When driving with new tyres, the surface may not yet have fully bonded with the road, which can affect grip; thus, careful braking is necessary to ensure control during the initial drive.

Recognizing all these situations helps enhance safety for all road users.