Which of the following best describe changes in the human population over the last 200 years
a. the population has been shrinking very quickly
b. the population has been growing very quickly
c. the population has been growing very slowly
d. the population has been shrinking very slowly

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