Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to tread water [title] Use both your arms and legs. [step] Make use of all four of your limbs with your body upright (vertical). If you turn your body horizontal and start kicking with your legs and paddling with your feet, you'll start swimming, not treading water.

Ending1: [title] Keep your head up and your breathing normal. [step] Keep your head above water and try to slowly regulate your breathing. Ending2: Come up short when trying to find a surface, or use all four arms to move. Just remember to stay level as much as possible. Ending3: Back-kick your feet as you prepare for water penetration. [substeps] You should stay submerged to avoid splashing. Ending4: [substeps] Dip out both of your feet into water while paddling with them to help keep them above water. When you don't have them, kick on your legs to keep your feet afloat.

Answer format: ending1/ending2/ending3/ending4