12. What function SPECIFICALLY causes oxygen to diffuse into blood, and CO2 to diffuse
into alveoli?
A. Blood carries oxygen to the lungs and CO2 away from the lungs.
B. Air in the alveoli has a greater concentration of oxygen, and lower concentration of CO2
than the blood in the lungs.
C. Blood passes into capillaries that supply body cells with oxygen, and pick up CO2 as cell
waste.
D. The heart pumps blood to the lungs

Subduction zones form when an oceanic plate collides with another oceanic plate or continental plate. the continental crust is lighter and less dense than oceanic crust. continental crust's density is approximately 2.7 grams per cubic centimeter. oceanic crust is thinner and the average density is about 3.3 cubic centimeters. when the two crustal plates converge the oceanic plate always bends and subducts beneath a continental plate. once the oceanic crust subjects, the rocks are subjected to changes in heat and pressure. because of this, we would expect to find rocks in the area of a subduction. a) clastic b) igneous c) metamorphic d) sedimentary