Question

warm - blooded: mammals maintain a constant body temperature. hair or fur: all mammals have hair or fur for warmth and protection. milk for babies: female mammals produce milk to feed their young. live birth: most mammals give birth to live babies (with a few exceptions like platypuses and echidnas). adaptations for survival: camouflage: helps mammals blend into their environment. echolocation: used by bats, dolphins, and whales to navigate and hunt. thick fur or blubber: keeps cold - climate mammals warm. diverse diets: carnivores: eat meat (e.g., lions, wolves). herbivores: eat plants (e.g., deer, elephants). omnivores: eat both plants and meat (e.g., humans, bears). parental care: mammals teach their babies survival skills. what is one characteristic all mammals share? choose the correct answer. they lay eggs. they have hair or fur. they live in water.

Explanation:

The text above lists characteristics of mammals. It mentions that all mammals have hair or fur for warmth and protection. Laying eggs is not a common characteristic (only platypuses and echidnas among mammals do so). Not all mammals live in water. So the key shared - characteristic is having hair or fur.

Answer:

They have hair or fur.