the two leading causes of death among the elderly are heart disease and

hey there!

so, when you eat, your teeth chew and grind food into smaller pieces. this is mechanical digestion. then reactions aided by digestive enzymes break down large food molecules into smaller molecules. this is chemical digestion. the two processes change the food into simpler substances that can be used by the body for raw materials and energy.

hope this

tobey

they deliver oxygen to the blood

the correct answer is b

i'd have to say the answer is probable the second option "the geosphere interacting with the atmosphere"