Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to protect your dog around backyard pools [title] Teach your dog to swim. [step] Not every dog knows how to swim. Many owners assume that their dogs know how to swim so they don't worry about them around pools.

Ending1: However, making this assumption can help you get the dog to do so more easily. Do several different activities so that the dog can learn how. Ending2: Dogs may be inexperienced and not know how to swim. They also may panic and not swim correctly. Ending3: Therefore, you don't know exactly how to get your dog to swim. Therefore, it's important to practice. Ending4: However, taking time to train your dog will help him, too. [substeps] Take out the proper swimming pieces before you go swimming to prevent splashing.

Answer format: ending1/ending2/ending3/ending4