They nurse them and teach them how to survive on their own.
Yes, mammals care for their young.
All mammals suckle their young. That is one of the defining characteristics that makes them mammals. Even egg-laying mammals (monotremes which include the platypus and echidna) suckle their young.
Yes. Kangaroos are marsupials, which are a sub-group of mammals. All mammals suckle their young.
Mammals give birth to their young for purposes of procreation. This is what ensures that the life cycle of the mammals is continued.
Your question seems to suggest that mammals that feed milk to their young are a subset of mammals. But all mammals feed milk to their young. That, along with the presence of hair, is the defining characteristic of all mammals, without exceptions.
Mammals feed their young by suckling until they can accept solid food.
Vertebrates with hair, giving birth to live young, and that suckle their young are mammals.
Yes, they are mammals. All mammals, except the platypus, have live young.
mammals
Mammals have hair and nurse their young. That's what makes them mammals.
mammals
Hippos are mammals. They have hair and give birth to live young and feed the young with milk.