Which two of these characteristics are examples of endoskeletons? a. scales in fish b. bones in mammals c. calcium-rich plates in echinoderms d. appendages in arthropods

Option B and option C are correct.

Explanation:

Endoskeleton - An internal support structure or skeleton is on the inside of a body, composed of calcium or mineralized tissue.

B. Bones in mammals - are endoskeleton, it supports the body in its shape.

C. Calcium-rich plates in echinoderms are acts like exoskeletons but most of the cases a thin tissue surround skeleton so it is an endoskeleton.

answer; i believe that the correct answer is (light);

the most common energy conversion is from kinetic energy to potential energy, and then from potential energy to kinetic energy.

later on comes the heat energy, mechanical energy, and other energy conversions.

this energy conversion is so common that we can find it in our day to day lives as well.

- one of the most common energy conversions involves the changing of potential energy to kinetic energy or kinetic energy to potential energy