How often does the earth rotate on it's axis

Which best describes the idea behind the "invisible hand"? producers decide what to make for consumers, which guides the economy. individuals seeking their own self interest benefit the economy as a whole. government sets policy for producers and consumers, which guides the economy. consumers decide what they need and want to buy, which guides the economy.

Why was frederick douglass encouraged by the dred scott decision?

Which organelle is marked with an x?