What essential nutrient is responsible for almost every function that keeps you alive?

Marijuana is an example of a(n) drug

Blood cells bring oxygen to cells and take carbon dioxide away. true or false

Health is as much a social as a biological concern. analyze whether or not healthcare is equally accessible to people belonging to all strata of american society. what steps has the us government taken to address this problem? suggest one measure that can lead to a comprehensive solution to this problem.