What factors the spanish defeat the aztec

First, Europeans unknowingly transmitted the smallpox virus to the Native Americans, who had no immunity for the disease. Smallpox killed hundreds of thousands of the Native Americans, which weakened the Aztec Empire and createdpolitical and social instability. Second, Hernan Cortes and his men had superior weapons. 

ANSWER = Diseases and More advanced weapons

The Food and Drug Administration tries to promote the general welfare by testing food to make sure it is safe before humans consume it.

Explanation: