Answer:
Biological warfare.
Explanation:
Mongol Empire used biological warfare method (black plague) to kill humans in the Crimean peninsula. Mongol troops threw plague victims into the city, thus contaminating the inhabitants. The Mongols were the first to use germ warfare. The Mongol army threw infected bodies into the attacked Crimean city of Caffa, and that led some of the survivors to flee and spread epidemic from Caffa to the Mediterranean Basin.
A vassal gave the lord military support and protection...In turn the lord gave a vassal fiefs.. (land)
<span>From the Spanish Empire in the New World came an influx of precious metals, which had profound economic effects. The flow became especially important in the second half of the sixteenth century, and consisted of both gold and silver, with the latter metal predominating. The Spanish went to great lengths to secure the entire supply for themselves and prevent any of their precious cargoes from falling into the hands of their rivals. Each year the plate fleet, bearing the bullion from the mines of Peru and Mexico, was accompanied to Spain by a convoy of warships, and during the sixteenth century no other nation ever succeeded in intercepting this fleet. Francis Drake was able, however, to rob Spanish treasure in Central America and in the Pacific.</span>
Based on this EMuseum document, two ways the Qin under Shi Huangdi attempted to control <span>China was through imperial control and through the economy. </span>
It would be D machines because during the industrial revolution In Europe the introduction of powered machines was very impactful
