sentence: Many mammals live in cold places.
sentences_before: Mammals are found on land and in water, and also in the air, where they compete with lots of other animals. Their ability to move from place to place and adapt has made them a most efficient group.
sentences_after: These mammals have thick hair or blubber to keep them warm. Others may live in rainforests. Some live in deserts, and still others are in rivers, lakes, and seas all around the world.
concept_name: mammal
headings: Mammal Modes of life