Crude oil beneath the earth is often under pressure because it is trapped under
a. coal deposits
b. water tables
c. nonporous rocks
d. porous rocks

Alow pressure system is formed when an air mass cools over a cool surface and sinks. true or false

On this map of the united states the letter h indicates high pressure and the letter l indicates low pressure . select the black arrow that accurately shows the direction of the wind.

Look at the map above. which of the following statement is true