Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to air fry bacon [title] Preheat the air fryer before adding the bacon. [step] Your air fryer requires a two to three minute preheating period. This allows the machine time to achieve the temperature necessary to begin cooking your bacon.

Ending1: [substeps] Make sure there are no coals visible when you start preheating the air fryer. This ensures fresh and crispy bacon will cook evenly. Ending2: For most models, simply set the air fryer to the desired temperature and wait at least two minutes before adding your bacon to the air fryer's cooking basket. [substeps] Operate your air fryer only on level, heat-resistant surfaces. Ending3: [substeps] Also be sure to add or remove any bacon pieces to allow them to cook more evenly. Make sure your air fryer is unplugged when you start cooking. Ending4: You may need to speed the process up if you have not heated the air fryer for a few minutes. [title] Flip the bacon and cook until one side of the bacon is crispy.

Answer format: ending1/ending2/ending3/ending4