When a candle burns, physical and chemical changes take place. the of the wax is a physical change

What is thought to have caused the mass extinction at the end of the cretaceous period?

Which is not a likely outcome after extensive irrigation of dry farmland? useless, unproductive soil salinization of the soil depletion of groundwater nutrient-rich soil

What is the inability of an individual or a society to achieve a minimum standard of living known as ?