Hello brokenheart1! ( I love your username, it's so aesthetically pleasing. )
The kind of primary source document that I find most interesting to analyze are diaries, because I like to see someone's perspective on a subject or time period. It can be quite interesting and gives me a first hand look on a matter through someone else's eyes and opinions.
I hoped that helped, I always enjoy getting brainliest when possible!
From Allikat74 :)
Answer:In 1947, Salk took a position at University of Pittsburgh, where he began conducting research on polio, also known as infantile paralysis. By 1951, Salk had determined that there were three distinct types of polio viruses and was able to develop a "killed virus" vaccine for the disease.
Explanation:
The Correct answer is C. From ever using a nuclear weapon again
Commercialisation led to growth of national agriculture and agricultural problem acquired national form. It brought about regional specialization of crops on an efficient basis. Commercialisation encouraged the production of some specific crop and favourably affected their distribution.
