Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to flutter kick [title] Hold onto a pool wall or lane marker. [step] Grasp a wall of the pool, a lane marker, or another stationary object that allows you to extend your body in the water behind it. Hold your arms out straight from the wall, with the rest of your body as horizontal as possible in the water.

Ending1: [substeps] Ideally, have your face submerged in the water so that your head is in the same line as your body. Obtain a snorkeling mask to make it easier to maintain this position without having to bring your face up for air. Ending2: Then turn your body so that your thighs or knees are facing forward. Your hands should be at about level with the wall at all times. Ending3: [title] Move your legs and arms while kicking. [step] Keep your legs bent at the knees and initiate a carefree and powerful flutter kick. Ending4: Push your feet towards the wall, moving the pool rope behind you at roughly equal intervals. [substeps] If doing a butterfly kick you should thrust your hips toward the wall, but try not to get your thighs too close to the top of the pool.

Answer format: ending1/ending2/ending3/ending4