Human activities
a. exacerbate the natural greenhouse effect
b. create the greenhouse effect
c. diminish the greenhouse effect
d. eliminate the greenhouse effect

Match the type of adaptation to the correct example, structural adaptation functional adaptation behavioral adaptation example type of adaptation elephants live in herds to protect their young leaves of a rain forest plant species have a pointed tip that enables rainwater to drain off easily. camels have nostrils that they can close snakes produce venom to kill prey and defend themselves. earthworms coil when touched, as part of a defense mechanism. human skin darkens with increased exposure to sunlight.

Acceleration is a direct result of a.) balanced forces b.) unbalanced forces c.) gravity d.) velocity

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