• Supranational Cooperation – Countries working together beyond borders • Centripetal Forces – Forces that unite people • Centrifugal Forces – Forces that divide countries • Crude Oil – Unrefined petroleum extracted from the earth • Nonrenewable Resource – A resource that cannot be replaced in a human lifetime • Oil Reserves – Quantities of oil that can be extracted profitably • Renewable Resource – A resource that replenishes naturally • Acid Rain – Rain formed from sulfur dioxide and nitrogen oxides mixing with water • Monsoon – A seasonal wind pattern that affects rainfall and drought • Primate City – A dominant city with twice the population of the next largest • Transboundary Pollution – Pollution that spreads across national borders • Population Density – Number of people per square unit of area • Elevation – Height above sea level