Which phrase describes the substitution effect?

a.
buying cheaper alternatives when a product becomes expensive
b.
replacing existing producers in a market with new producers
c.
replacing existing products in a market with higher-quality products
d.
substituting existing technology with a new technology to produce more goods

World war i brought increased immigration to the united states from which country? germany france italy mexico

“[the city’s engineers excelled in areas] neglected by the greeks, such as the construction of roads and aqueducts, and of sewers that could wash the filth of the city into the tiber. they have built paved roads throughout the country, leveling ridges and filling up hollows, so as to make possible the movements of heavily loaded wagons. . and such is the quantity of water brought in by the aqueducts, that veritable rivers flow through the city and its sewers: almost every house has cisterns, waterpipes, and copious fountains.” —strabo, as quoted in empires ascendant: time frame 400 b. c.–a. d. 200 cisterns are tanks that hold water until it is needed; if a house has a cistern, it is likely to also have a. aqueducts. c. a swimming pool. b. a fish pond. d. sinks and faucets.

Someone who accepted the beliefs of social darwinism would have also agreed with which of these statements?