State three types of skeleton?

Hydrostatic Skeleton. A hydrostatic skeleton is a skeleton formed by a fluid-filled compartment within the body, called the coelom.

Exoskeleton. An exoskeleton is an external skeleton that consists of a hard encasement on the surface of an organism.

Endoskeleton. An endoskeleton is a skeleton that consists of hard, mineralized structures located within the soft tissue of organisms.

Explanation: thx for the points ;)

i believe the correct answer from the choices listed above is the first option. the scientists need to look at the   validity of data, claims, hypotheses, and observations before  developing an argument. they base their arguments on facts that are present and they make sure they have proofs. 

explanation:

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.