Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to do general maintenance on airsoft gas blowback pistols [title] Take the magazine out and separate the slide from the actual gun. [title] Take a cotton pad or shirt and make sure to clean out the parts. [step] When you first get the gun, some grease will get into it during shipping.

Ending1: It will give you a clean, oil-free place to work. [title] Put silicone in the magazine place. Ending2: [title] While holding the gun steady, take a short deep breath. [step] Shift the barrel away from you for several seconds. Ending3: Clean it with the cotton rag or shirt. [title] Take some silicon oil and start lubricating the gun. Ending4: Use a lens cleaner or just a $70 bottle. [title] Paint the barrel with a thin layer of the cleaner or paint with a gun oil.

Answer format: ending1/ending2/ending3/ending4