The layers of the atmosphere are determined based on air temperature, which has to do with the energy of the molecules in the air. where does this energy originally come from?

What is the approximate circumference of the circle shown below? 12.2 cm

Given: circle a externally tangent to circle b. how many possible common tangents to circles a and b can exist? 2 3 4

Which statements describe sustainable development? multiple answer choice -fishing does not remove more fish from water systems than can be replaced by the number of fish that will be born to replace them. -sustainable development is development that is designed to improve the economic conditions in less-developed countries. -sustainable development is mainly a regional issue. -sustainable development means water is used at a rate that won't reduce the amount available for future use. - sustainable development policies only need to be concerned with environmental protection. - trees cannot be cut down faster than the number that will be replaced by new growth.