Please choose the correct ending to complete the given sentence: Health: [header] How to use an oxygen tank [title] Slide the plastic covering off of the top valve on your tank. [step] There may be a plastic sheath that fits around the top nozzle on your oxygen tank. Before you can attach the regulator to the tank, you'll have to remove it.

Ending1: To do so, simply flip the tank upside down on a pipe. Use a rubber glove to pry off the sheath. Ending2: The tank will have a brass panel that covers the valve. [substeps] In order to apply the fluid, you'll need to either carefully push this panel off, or you could leave it on. Ending3: Usually, you can simply slide the piece off or you may have to peel it away from the nozzle. [title] Line up the regulator with the top valve on the tank. Ending4: Before you attach the regulator, locate the small metal clip located above the valve and slide it off of the top valve. [substeps] Don't worry about this part.

Answer format: ending1/ending2/ending3/ending4