Please choose the correct ending to complete the given sentence: Snow tubing: A person ski on a hill wearing dark winter clothes. the person

Ending1: skis in the snow to open the chute to air the ski. Ending2: ski on the snow, but only the feet and sometimes the face is show. Ending3: lines up the ski slide rails on his ski. Ending4: skiski on the country slope while covered with snow in high altitude, and quickly passes above the pine trees, then the person continue on the mountain covered with snow.

Answer format: ending1/ending2/ending3/ending4