2. dolphin is a mammal because dolphin are warm blooded, and instead of laying eggs they give birth to Thier young's and feed them milks.

3. cold blooded animals -can be defined as a animals that cannot regulate Thier internal body temperature with the change in the environment

while warm blooded animals- are defined as animals that can regulate and maintain constant internal body temperature.

4. animals have played an important role in the providing, food, fiber, transportation, and work and eventually as models for comparative researchs.

5.animals can be pets, so pets can help manage loneliness and depression by giving us happiness.

Explanation:

hope it can help 〜(꒪꒳꒪)〜