50 points

which system is responsible for the exchange of oxygen and carbon dioxide?

a. skeletal
b. circulatory
c. respiratory
d. endocrine

Which statement describes a way in which the digestive and excretory systems work together? a. the nephrons absorb nutrients from food going to the large intestine. b. the excretory system balances blood gases in the small intestine. c. the intestinal villi filter blood and send wastes to the bladder. d. the excretory system balances the salts and water obtained from digested food

What is responsible for the uneven heating between the poles and the equator on any given day

Which process in respiration happens first? a)pyruvate processing b)electron transport chain c)krebs cycle d)glycolysis