A(n) , such as oxygen or carbon, is a pure substance.

The leopard frog and the pickerel frog are two closely related species. in areas where their ranges overlap, the frogs will remain separate species if they

Which of the following can be reduced by the use of renewable energy sources? a. social costs b. economic costs c. environmental costs d. all of the above select the best answer from the choices provided a b c d

What is the correct term for an area of rotating currents in an ocean? when ocean currents combine, they create an area of rotating currents called an