Question

why?
communicable diseases are spread between individuals by different methods, but they are all caused by pathogens, which are commonly called \germs.\ knowledge of pathogens and the ways in which they can be spread helps humans understand and prevent disease outbreaks.
model 1 - the 1854 london cholera outbreak

1. model 1 is a map of an area in london where a large number of cases of cholera occurred in 1854.

a. how many water pumps are shown on the map?
b. what do the black boxes represent on the map?
c. what do the relative sizes of the boxes represent?

Explanation:

• For part a, we can directly count the number of water pump illustrations on the map.
• For part b, the text at the top of the map indicates that the black - box - like elements are related to cholera deaths.
• For part c, the legend on the map clearly states that the size of the boxes is about the relative number of deaths.

Answer:

a. 4
b. Deaths due to cholera.
c. The relative number of deaths due to cholera.