Final answer:
Every time you leave your vehicle, you should leave it in gear (if it has manual transmission), turn the steering wheel as far to the left as you can, and apply the parking brake.
Step-by-step explanation:
Every time you leave your vehicle, you should do all of the above: leave it in gear (if it has manual transmission), turn the steering wheel as far to the left as you can, and apply the parking brake. These actions ensure that your vehicle is secure and will not roll away when parked.