to me letter C best describes the role of Viceroys in Spain's American empire :)
hope this helps :)
Answer:
The Dred Scott decision was effectively nullified in 1865 by the passage of the 13th Amendment, which abolished slavery, and by the 14th Amendment in 1868, which guaranteed full citizenship rights to all Americans, regardless of race.
Pierre Roux, Emil Behring and Paul Ehrlich developed effective treatment of diseases by finding the antibody required to kill the disease.
Answer: found the antibody and developed a serum t prevent disease
<u>Explanation:</u>
Initially the study of why disease are caused led to the study of disease causing organisms and how our system fight to prevent the disease. This led to the discovery of immunology. The deleterious effect caused was due to the pathogen and the pathogen elaborated their protein toxins causing serious illness.
In olden days when a disease called diphtheria was killing thousands of children there were many scientists who rose to study the disease. Emil Behring, Pierre Paul Roux and Paul Ehrlich studied about the toxic effect created by the lethal disease. They studied that the antibody required to kill the diphtheria toxin can be cultured in animals. They developed an effective serum to treat the disease diphtheria which cured many children.
By the ratification of another amendment. Because repealing amendments must be proposed and ratified by one of the same two methods of regular amendments.
Hope it help!❤️
