Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to teach your dog to play dead on command [title] Teach your dog the' down' command before teaching him how to play dead. [step] Playing dead involves your dog lying down. Before he can learn this trick, he should be comfortable with the command to lie down.

Ending1: [title] Choose a comfortable area to train your dog. [step] Preferably, this area should also be quiet so that your dog does not become easily distracted. Ending2: [substeps] Place your dog on his back with his chin on the ground. He should then lie down and stare at you. Ending3: To teach him the' down' command, put your hand outside his shoe that you want him to bite off. The dog can hear your hand and slip into the habit of reflexively biting you. Ending4: Because he is practicing this trick a lot, he will have plenty of flexibility when just lying down. [substeps] Point your dog to his back and lay one hand on his belly.

Answer format: ending1/ending2/ending3/ending4