What activitiy contributed to the spread of the black death

Trade was what spread it the most. People were being in contact with other people and without knowing they spread the germs. The rats and fleas spread it too but that was spread through animals. The rats and the ticks would bite the people and they would be infected. Relatives would try to help them but without knowing they'd be sick too out of nowhere.

How am i supposed to know your lecture

Answerscripps institution of oceanography; i believe this is correct plz check first good luck;