Whatever fossil is at the lowest layer is the oldest cuz the old fossils lived along time ago and when they died the fossils were buried.
I believe its b , hope it helps
Answer: C.
Air masses that are hot and dry, and are responsible for heatwaves of summer in the western half of the United States.
Explanation: Air masses have fairly uniform temperature and moisture content in the horizontal direction (but not uniform in vertical). Air masses are characterized by their temperature and humidity properties. The properties of air masses are determined by the underlying surface properties where they originate.
Air that stands over the Caribbean Sea, for example, becomes a warm, humid maritime tropical air mass, while air that lies in the Arctic regions of northern Canada takes on the cold and dry characteristics of its surroundings and becomes a continental polar air mass.
