4 because you need to determine everything in the text not move on.
The fact that medicine and the understanding of health was not developed enough for them to realize how the human body worked and so while they felt they were helping they actually were just making things worse, such as the bleeding out of people which was done because it was believed that if you were coughing up blood that must mean you had too much blood in your body so they cut people in order to drain blood and "balance" the fluids. Also many people made long pilgrimages of mobs everywhere lashing and whipping themselves because they believed that the plague was punishment from God and that by harming themselves was there way of trying to repent. However all this did was increase the concentration of people with plague in areas and that mob traveled all over allowing spread to be much easier. There was also the fact that fleas were extremely common and people only took baths like twice a year and that was considered being clean. So people had ticks and fleas all over their body so they did not suspect that being the cause.
That's not everything but it is a little bit that can hopefully help.
Daniel Hale Williams' motivations were to succeed in the first heart surgery and to overcome discrimination.
He contributed to science by helping advance the needed technology for heart surgeries-- after he complete the first ever heart surgery, scientists looked into antibiotics and proper technology so the heart surgeries in the future would be much more easier.
3rd person is writing about someone, 2nd is switching off, and 1st is themselves taking about themselves
