Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to clean smoke off of a ceiling [title] Create a source of ventilation. [step] When dealing with caustic cleaning materials, you make sure you have good airflow in the room. You can accomplish this in many ways, but the most basic way to create ventilation is to open a window and turn on a fan.

Ending1: Keeping the fan turned off allows steam to escape and this can create a much greater and improved ventilation. [substeps] Making multiple vents on the ceiling is a great idea if you are cleaning a lot of window areas. Ending2: Ventilation is vital to any home to help disperse smoke and prevent contamination. If you don't have a fan, you can install two or three hurricane-style vents (as opposed to the single one you can purchase at home improvement stores) in your home. Ending3: [substeps] If the room in question does not have a window, be sure to leave the door open and have a fan on its highest setting. [title] Place a drop cloth beneath the cleaning area. Ending4: In a hallway, shut a door so hot air can flow through without affecting the noxious fumes. [substeps] Try to eliminate any obstructions from ventilation near doorways and windows.

Answer format: ending1/ending2/ending3/ending4