Please choose the correct ending to complete the given sentence: Health: [header] How to choose a toothbrush [title] Make sure your toothbrush works for the shape of your mouth. [step] Based on past toothbrushes, you should have some idea of the general shape of your mouth. Some mouths are more narrow or wide than others, and you need a toothbrush that works for your mouth and teeth.

Ending1: If your mouth doesn't feel good, a toothbrush with a wider opening will just fill in the gaps where those areas haven't been covered by a brush. Depending on the shape and size of your mouth, you might want to start with a smaller toothbrush. Ending2: [substeps] If your mouth feels wider than normal, you may benefit from a toothbrush with a wider applicator. So is a smaller applicator, which will look a lot like a dog's toothbrush. Ending3: [substeps] You want a brush that can comfortably reach the back of your molars. The shape of your mouth, and whether it's wider or narrower, will affect how easily a given brush can reach your molars. Ending4: It's imperative that you always brush your teeth with a toothbrush that is specifically for your mouth. [substeps] Toothbrushes typically have a brush attachment, and these can be purchased at pharmacies or at a local department store.

Answer format: ending1/ending2/ending3/ending4