Through hemoglobin transport in blood, material exchange is carried out on the alveolar membrane.
Ice caps so it would be D
Hope it helps :-)
Answer:
Described by a redox reaction below
Explanation:
Iron(III) oxide is an ionic compound, since it consists of a metal, iron, and a nonmetal, oxygen.
Ionic compounds are formed when metals lose their valence electrons in order to have an octet in their previous shell and donate them to nonmetal atoms, so that nonmetals fill their outer shell to have an octet.
As a result, positive ions (cations) and negative ions (anions) are formed. When iron reacts with oxygen, the following reaction takes place:

This is a redox (oxidation–reduction) reaction, since we have electron loss and gain. Four iron atoms lose a total of 12 electrons to obtain a +3 charge in the final compound, while 3 oxygen molecules gain these 12 electrons to become 6 oxide anions with a -2 charge.
Answer:
Pumice is a light colored, porous igneous rock. It forms during volcanic eruption occurring under water. It is an aggregate of concrete. Because of their porous nature they float over the surface of water. With time the pumice rocks undergoes with several changes including weathering, erosion, and transportation. The extent of heat and pressure, making the sediments of the pumice rocks into metamorphic rocks distinct in the chemical and physical composition of the parent material.
As the earth is in the form of a sphere, the angle of incidence of the sun's rays at the earth's surface increases from the equator towards the poles and therefore the amount of heat received on a GIVEN AREA diminishes in the same direction. Temperature is therefore normally hottest near the equator and coolest near the poles.