Please choose the correct ending to complete the given sentence: Health: [header] How to maintain white teeth [title] Avoid or reduce exposure to highly acidic foods. [step] Acidic foods can weaken the enamel, and make teeth more likely to stain. This is part of the reason that coffee, tea, wine, and soda can all stain your teeth.

Ending1: Don't eat these foods while your mouth is at risk of staining. Focus on sucking in a big gulp of some white food to maintain your white teeth. Ending2: By limiting or preventing acidic foods from coming into contact with your teeth, you can reduce the possibility of a stain. [substeps] You can substitute milk and soda to make a palmetto or lactose free drink that has an acidic taste. Ending3: Also make sure to wait at least thirty minutes before brushing your teeth after eating or drinking something acidic. [substeps] Fruits that are especially harsh on teeth include lemons and citrus. Ending4: [substeps] Make sure to drink mojito detox drinks, or some other acidic beverage such as campari for sports drink. Choose electrolyte-based drinks, including beer, espresso, etc.

Answer format: ending1/ending2/ending3/ending4