Microscope changed the course of scientific research by enabling scientist to see things and organism that can not be seen by our bare eyes
C. Address the major health concerns in the USA.
If that rate of your body is too hot u feel cold; and if your body is low (cold) you feel warm.
Explanation: Chemicals
There are four primary chemicals in the brain that effect happiness: dopamine, oxytocin, serotonin, and endorphins. By designing gamified experiences that activate these chemicals, you can increase your users' happiness and loyalty.