Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to fill an air tank [title] Take your air tank to an air compressor. [step] Full-service gas stations or truck stops are the most common locations that have air compressors. You can use the same pump motorists use to inflate the tires on their vehicles.

Ending1: [substeps] If you are out of town and don't have access to a gas station or pump, it might be an option to do your own pump pumping. [title] Plug your air meter into your air tank. Ending2: A full-service gas station or truck stop is safer than a flat part of an airport without air. [title] Let air out of the tank by steering using the brake pedal. Ending3: [substeps] Check the tire patterns to see if there is one large tire that you will need to fill up. If there is not, or it has been punctured, you are running out of gas. Ending4: [substeps] Inspect your air tank for damage before filling it, and get a new one if you see any cracks or rust. You may also be able to get your tank filled at scuba shops, paintball locations, and some sporting goods stores.

Answer format: ending1/ending2/ending3/ending4