How might natural variations in humans have contributed to their ability to survive diseases such as the Black Death

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

just go with your heart buddy

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