I need help on questions 2 and 3 please. Your help would be deeply appreciated!

How is the carbon cycle related to global warming ?

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

Deserts (especially true deserts) are not easy places for animals to live. animals who live in them often have special features that them survive. which adaptation would be for this group of animals? a) keen eye sight b) short, narrow legs c) tolerate heat d) webbed feet