Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to keep a dog in the yard [title] Observe your dog while he is in the yard. [step] Figure out how your dog is getting out of your yard, sit by a window and watch him while he is outside. Try not to let him see you or he may not reveal his escape route.

Ending1: [substeps] This could be by window or inside your home, or it could be through a regular door in your home with a dangling shutter to allow him outside. [title] Watch him as he moves out of your yard. Ending2: Practice a trick like lifting on a jump bar to see where he goes. The jump bar will help you spot where he is going and what he is doing when you catch him. Ending3: As you watch, pay attention to where your dog goes and what he does. This should give you clues about his preferred method of escape. Ending4: He may retreat to another area somewhere in the yard and get lost. [title] Follow your dog's lead when it comes to food.

Answer format: ending1/ending2/ending3/ending4