how do dolphins and whales breath as they dont have gills? why do they come to the surface of the water time to time?

Dolphins and whales breathe through lungs. They have nostrils, called a blowhole, located on top of their heads.

Whales and dolphins use their lungs to breathe. That's the reason why they come to the surface of water time to time.

Explanation:

i believe that the answer is c.

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