Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to set up an oxy acetylene torch [title] Clean the nozzle on the head. [step] This should be done with a fine, round metal file. Just make sure that this nozzle hole is unobstructed.

Ending1: If holes are obstructed, a torch tip bore cleaning tool may be necessary. [title] Securely fasten the " head " of the torch on the end of the hoses. Ending2: Normally, oxy acetylene conducts voltages much quicker than oxy butane. You can repair the nozzle early, of course, but it is difficult to be vigilant for if you are using a dirty nozzle. Ending3: From here you can move on to fastening the pointed end to the head. Just make sure that you do not make the screw too unnoticeable. Ending4: [title] Allow the oxy acetylene torch to bleed into the ignite hole. [step] Do this periodically; this will only happen when the torch is heated up enough.

Answer format: ending1/ending2/ending3/ending4