Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to make whiskey ice balls [title] Understand what you're going to be doing. [step] There are two important factors to produce clear ice: water quality and freezing method. [substeps] Water has trapped gas particles and impurities in it that lead to that cloudy appearance.

Ending1: If ice is missing, water can build up and collect in the ice. Mostly the ice gels from this supply is being processed into the ice pot; the cool water is being cooked/added to the ice. Ending2: Removing the gases and impurities is the first step to achieving clear ice; therefore pure, distilled water is needed. The second crucial step to achieving clear ice is the freezing method. Ending3: Ice can produce a sour, dry ice-like thermometer. One of the best guns to use for baking ice is the splash bottle. Ending4: Water is produced in a process called' combustion'. The gas is destroyed, and there are no going back steps necessary to produce water.

Answer format: ending1/ending2/ending3/ending4