Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to tape up stubborn german shepherd puppy ears [title] Look at the structure of your puppy's ears. [step] Simply put, not all german shepherd puppy ears are created equal. For example, thin ears that do not have much cartilage may not be stiff enough to stand upright on their own.

Ending1: On the contrary, thicker ears probably have enough cartilage and muscle development to stand up more easily. [substeps] Ears that are widely spaced on your puppy's head may have a harder time standing upright. Ending2: However, thick or stubby ears may become stubborn. [substeps] You should also weigh the puppy's head up against your right shoulder to see if it weighs more (you can weigh the dog just in kilograms). Ending3: [title] Figure out your dog's thickness. [step] Stubborn breeds love solid, but thin ears can easily become unreasonable. Ending4: Look at the structure of your puppy's ears! If they have a lot of cartilage, they may need to be moved for support. [title] Recognize that ear sizes for german shepherds are not always tight.

Answer format: ending1/ending2/ending3/ending4