Answer:
I'm confused I'll answer your question but is there an article or passage that goes along with the plot diagram because if not I have nothing to go on.
It's supposed to be Our neighbors are across the street.
Joans Edward Salk became famous for developing a polio vaccine?
Polio is a contagious disease that has mostly been eradicated
In the 1940,s, polio was widespresd.
