Which of the following statements correct identifies the term "humus"? Humus is the organic material found in soil C. Humus is precipitation that contains a high
that results from plants and animals that die concentration of pollutants.
and decay.
b. Humus is the groundwater that is not
replenished by rain.
d. Humus is a means of water transportation
that involves the relocation of ground water
to the surface.

Using complete sentences, describe the central economic problem facing all humans. why does this require people to make choices? how can this result in opportunity costs?

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.

Match the region in column 1 to the river in column 2