In 2006, _ of all high schools operated under exclusive contracts with soda companies, and by 2012 more than _ of all school districts served fast food.

Its either c or d. i would go with d though, because im not sure if its legal in all of the us

People who utilizes the progression principle will ensure their exercise program increases in frequency, intensity, time, and type. the changes need to happen gradually in order to ensure they make gains in their fitness program. a person who doesn't utilize the progression principle can still gain health benefits from exercising, but will not continue to improve in cardiovascular fitness.