Please choose the correct ending to complete the given sentence: Health: [header] How to make a pipe out of a pen [title] Obtain a cheap click pen with a removable cartridge and a metal tip. [step] The metal tip is crucial; this is where you will be burning your pipe tobacco. If the tip is plastic, you will ingest toxic fumes from the burning of plastic.

Ending1: The pen must be easily dismantled as well. [substeps] The tip of the pen is the small metal cone that surrounds the point when you're writing. Ending2: [title] Glue the cartridge pieces to the pen. [step] Once you have glued the cartridge pieces to the pen, punch holes into it and squeeze the contacts so they don't pop out. Ending3: You can purchase a cheap pen from a craft store. Take the pen your to make it lightweight. Ending4: If the tip is paper or styrofoam, the ink will bleed out of the pen. [title] Take a pen, and place it under the pen body.

Answer format: ending1/ending2/ending3/ending4