The central economic problem that all humans face is A shortage
B. scarcity
C. opportunity cost
D. the factors of production

Distance that the transcontinental railroad covered from omaha to san francisco.

How much water is in the ocean in cubic kilometers

Short answer/constructed response: respond to the question in 3-5 complete sentences. give details or examples to support your answer. attempt to answer all parts of the question in paragraph form! using the source 1 map, pick two of the 1800's territorial acquisitions you believe were the most important in the development of the united states. provide at least two reasons per territory to explain why you think they were the most important.