Answer: planning complex cities.
Explanation:
B and C. Garbage was a MAJOR issue because factories had no where to to dump all the garbage they had. Also pollution because of the steam/gas powered machinery. Also, houses right next to industrial areas were cheap due to the factory of poor land value, and pollution
For number 22, it's austrians, Italians, Czechs, and Hungarians. And for number 24, the answer is C.
The U.S wanted to buy New Orleans witch was part of Frances territory. Who ever had the Louisiana territory basically had New Orleans. The U.S want the new Orleans port for trade so they offered to buy New Orleans. France was in a war with Britain and they needed money so Napoleon offered to sell the whole Louisiana territory to the U.S. (at that time it was only 17 cents an acre so the U.S bought it) <span />