Answer:
90%
Explanation:
When the Europeans arrived, carrying germs which thrived in dense, semi-urban populations, the indigenous people of the Americas were effectively doomed. They had never experienced smallpox, measles or flu before, and the viruses tore through the continent, killing an estimated 90% of Native Americans.
I'm not sure that this is 400 words but this is what I came up with.
Answer:
The correct answer to this question: Evaluation of evidence should be based solely upon study design:____, would be: false.
Explanation:
According to research done on the topic, there are many other issues that must be taken into account when evaluating the results of a research study, be it clinical, or in the field, and not simply study design. Study design allows the evaluators to assess the style, the form, and the way in which the study was carried out to reach results, but evaluating results, the evidence gathered only based on how the study was designed would be wrong. This evidence evaluation should focus primarily on how the intervention worked on a certain study, and whether it was carried out in such a way that would yield the proper results, without bias.
Answer:
chlorination
Explanation:
The use of chlorination to treat drinking water, which began in 1913, reduces the incidence of waterborne diseases.