Having to meet unlimited wants and needs with limited resources is called A cost
B. scarcity
C. a shortage
an onnortunity cost

Please help :} and explain why I need to know

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite

At which point on the diagram do convection currents occur to drive plate movement?

Which ecosystem best fits the characteristics listed below? which ecosystem best fits the characteristics listed below? ii. seasonal migrations of millions of wildebeests, zebras, and elephants iii. large numbers of predators, such as lions iv. acacia trees and grasses a. the congo rainforest b. the african mangroves c. the serengeti grasslands d. the sahel