Please choose the correct ending to complete the given sentence: Longboarding: . two young boys wearing helmets, holding skateboards and carrying backpacks

Ending1: slide down a snowy embankment and down a hill towards a steep drop. Ending2: walk down a freeway. Ending3: begin skateboarding down a sidewalk together. Ending4: are walking through an area that is heavily filled with leaves and trees.

Answer format: ending1/ending2/ending3/ending4