In perfect​ competition, a​ firm's marginal revenue is A.
equal to price.
B.
the change in the​ firm's total revenue divided by the change in the​ firm's output.
C.
the additional revenue the firm earns when it sells one more unit of output.
D.
All of the above.
E.
Only A and B above.

Children begin to use tools at about what age? a. 18 months b. 2 years c. 1 year d. 6 months

The tea party movement is a. an official third party that challenges both democrats and republicans in national elections. b. an organized challenge to incumbents in the republican party by the most conservative wing of the republican party. c. an organized challenge to incumbents in the democratic party by the most liberal wing of the democratic party. d. an offspring of the green party that runs for state and local office in many midwestern states. e. the now defunct party that gave way to the republican party at the end of the “second party system.”

Which statement best explains the "culture of life? " (plato) a. it is the belief that all life is sacred and the implementation of policy in line with that vision. b. it is the idea that human embryos should be used to find cures to medical conditions. c. it is the belief that god created the world and that no one should meddle in affairs of life and death. d. it is the belief that human beings have the right to determine when and how they should die.