Please choose the correct ending to complete the given sentence: Health: [header] How to smile when you think you can't smile [title] Use the mirror. [step] If you get used to having a smile on your face, it will come more naturally when you need to make it happen. Even though there will always be those times where it is hard to smile, you can make it easier by having your smile ready.

Ending1: [substeps] Use any mirror that you plan to use and sit comfortably in it while you feel the urge to smile. Press your cheeks together and your smile should clearly show up on your face. Ending2: [substeps] Focus on keeping your teeth white, and letting your teeth show. This will distract you from your bright smile. Ending3: The mirror can be your best friend in this case. Take a few minutes (each day, or every week) to check yourself out. Ending4: [substeps] Use it during times when you can smile, like important conversations or work. Keep smiling when someone asks you a question, even when there's no need for an answer.

Answer format: ending1/ending2/ending3/ending4