Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to feed newborn kittens commercial milk replacer [title] Test the kitten's temperature. [step] It can be dangerous for a kitten to be fed cold milk when it is already cold. Feel the pads of the kitten's feet and place your finger in the kitten's mouth.

Ending1: If it's too cold, your kitten is likely to nip at your finger. Have someone hold a temperature-safe bottle near you, so you cannot attempt to feed the kitten ice cold milk during the day. Ending2: Check to see if the kitten's breath registers as warm as it should. [title] Moisten kitten nipples or other ducts. Ending3: If either is too cold, slowly warm up the kitten. [substeps] This step is particularly important if you have found the kitten outside. Ending4: Check for blood in the kitten's mouth. [title] Understand that the feeding method can be difficult.

Answer format: ending1/ending2/ending3/ending4