Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to tie a zeppelin knot [title] Place two pieces of rope on a flat surface with the tail ends facing one another. [step] The tails of each rope should be facing one another. The two ropes should form roughly a straight line, with a small break in between the line.

Ending1: There should be no more than one or two pieces separating the tails from one another. Position the split ropes so that they cross the tailless end of the rope. Ending2: [substeps] The ropes should both be fairly long, at least 3.5 inches (11 cm). [title] Add 3-7 inches (7.6 cm) to the rope. Ending3: [substeps] It will be difficult to tie two ropes together. Altering the length of the zeppelin knot will only result in the opposite end of the rope drawing the strings taut, creating a slip knot. Ending4: [substeps] If you're working outside, you may not be able to find a flat surface. Simply look for the flattest bit of ground you can find.

Answer format: ending1/ending2/ending3/ending4