Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to ride a fixed gear bike [title] Lift the back wheel off the ground to position your pedals. [step] Lifting the back wheel off the ground will prevent your bike from rolling while you move the pedals. One pedal should be in front of you so that you can propel yourself forward when you step on it.

Ending1: The other pedal should be buried in front of you and be positioned between the front and rear wheels. [substeps] Lay your feet flat on the ground to build up enough weight to get you moving. Ending2: Position your hips over your bike's hind legs and straighten your feet as well. [title] Understand the driving and turning techniques of a fixed gear bike. Ending3: Another pedal should be behind you so that you can get into a comfortable position to lift your front wheel. Make sure your tire is level, or else you might damage the bike. Ending4: Rotate the pedals with the back tire lifted up and put the pedals in the right position. [title] Put your foot in the toe clips and start pedaling.

Answer format: ending1/ending2/ending3/ending4