Please choose the correct ending to complete the given sentence: Cars & Other Vehicles: [header] How to repair minor aircraft skin damage [title] Draw a circle around the damaged area. [title] Drill a pilot hole in the circle so a bigger unibit can easily drill into the aluminum. [title] Using a preferred method cut out the aluminum within the circle drawn around the damage.

Ending1: [step] Push (or otherwise stab) a pilot hole into the center of the aluminum with a drill bit. [substeps] Screw on large nuts (the larger the better) and reinforce the area with tack screws. Ending2: [title] Roll the aluminum back into a rigid loop. [title] Cover the top of the circle with masking tape (the tape may be under various impacts from breaking screws). Ending3: [step] Debur the newly cut hole. [title] Cut out a circular patch from a sheet of aluminum that is the same thickness and the original aircraft skin. Ending4: [title] Mark the ground you're going to start at. [title] Weld to the ground with a pilot hole ½ to 1 inch (1.27 to 2.54 centimeters) thick.

Answer format: ending1/ending2/ending3/ending4