Please choose the correct ending to complete the given sentence: River tubing: Several people are floating on tubes down a river. they

Ending1: all look like they are in a tube going down a hill. Ending2: pull themselves through the water. Ending3: move in unison on the water water. Ending4: lay back in the tubes, riding the waves as they go.

Answer format: ending1/ending2/ending3/ending4