Answer: cold, pneumonia, harsh winters
Explanation:
Answer is B, the railroad system going through the cities.
Answer:
The Aztec ruled over a large Empire that included most of Central and Southern Mexico. They had subjugated other peoples like the neighboring Tlaxcaltecas, who were in fact crucial for the Spanish Conquest.
The Aztec were often very ruthless against their subjects. They extracted onerous economic tribute, and also practiced human sacrifices, often killing people from the subjugated tribes.
The territories governed newly acquired land while the U.S. was still expanding its borders.
Africans played a direct role in the slave trade, kidnapping adults and stealing children for the purpose of selling them, through intermediaries,
