Answer: d ribosomes
Explanation: Ribosomes help make protein which helps make enzymes
Upper surface of base of the skull
the intercourse of a human or animal to make babies
The flow of energy starts in in you arms. You put your hands together, and use your arms to move your hands back and forth, this is kinetic energy. Your hands rubbing together causes the molecules to bump into each other, this is friction. As the molecules bump into each other they begin to move faster, and the fast movements of the molecules is what creates heat.