Please choose the correct ending to complete the given sentence: Youth: [header] How to choose your toddler's first backpack [title] Make sure your child can carry a backpack. [step] Backpacks can shift your child's center of gravity, so they'll need to be good walkers before they start wearing one. If your toddler still stumbles regularly and has trouble carrying things while walking, they may not be ready to carry a backpack.

Ending1: [substeps] Keep the backpack on your child's back in case they stop and walk at a height where they're able to carry a backpack. Place your child on their seat so that they're not bending backward or swaying to one side. Ending2: [title] Ask if the school has any requirements. [step] Some preschools and daycares don't allow wheeled bags, large backpacks, or bags with characters on them. Ending3: Avoid backpacks that move your toddler's center of gravity so they can more easily carry smaller items on. [title] Buy a toddler backpack that is available in bundles. Ending4: [substeps] While backpacks come in various sizes, backpacks that are slightly wider are the easiest to carry. Avoid backpacks that are too big, but ones that are a bit wider so they can carry briefcases.

Answer format: ending1/ending2/ending3/ending4