Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to clean the inside of a bottle [title] Fill your bottle less than ¼ full with gravel or rice. [step] If you choose rice, use raw, uncooked rice. If you choose gravel, choose a size in between sand and pea gravel.

Ending1: Look for enough value in your bottle that if you change your measurement once, it becomes a pellet-like object. [substeps] Gravel is a good choice if you want decorative table tarps. Ending2: Don't worry-you'll be removing many of the food particles that other metals like lead dust and acids can miss. All you need to do is gently press down on the gravel to completely dislodge the most food particles from the inside of the bottle, then return to the same place in your bottle that the bottle containing the water. Ending3: [substeps] If you choose rice, choose ground or uncooked rice. Otherwise, you can select potable or uncooked rice. Ending4: You'll want the gravel/rice to reach all the nooks, crannies, and corners of the bottle. [substeps] This method is great for irregularly-shaped bottles, as the gravel/rice will reach areas that may otherwise be hard to clean.

Answer format: ending1/ending2/ending3/ending4