Answer:
Traders from Asia
Step-by-step explanation:
The Black Plague was introduced to Continental Europe by trading ships bringing vermin, illnesses, and rodents along with consumer goods. When an unknown bacteria or disease is brought into a new environment (like Asia to Europe) the bacteria adapts and doesn't know how to respond initially. A bacteria that may not have affected Asia could easily affect Europe because the organism is unknown. This accounts for the mass spread of the virus and its severe symptoms.
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