Article: During the years 1940-1955, the rate of decline in the U.S. death rate accelerated from 2% per year to 8% per year, then returned to the historical rate of 2% per year. The dramatic decline in the immediate post-war years has been attributed to the rapid development of new treatments and vaccines for infectious disease that occurred during these years. Vaccine development continued to accelerate, with the most notable achievement of the period being Jonas Salk's 1954 development of the polio vaccine under the funding of the non-profit National Foundation for Infantile Paralysis. The vaccine process was never patented, but was instead given to pharmaceutical companies to manufacture as a low-cost generic. In 1960 Maurice Hilleman of Merck Sharp & Dohme identified the SV40 virus, which was later shown to cause tumors in many mammalian species. It was later determined that SV40 was present as a contaminant in polio vaccine lots that had been administered to 90% of the children in the United States. The contamination appears to have originated both in the original cell stock and in monkey tissue used for production. In 2004 the United States Cancer Institute announced that it had concluded that SV40 is not associated with cancer in people.

Question: Who created the polio vaccine?
Ans: Jonas Salk

Article: As in arthropods, each muscle fiber (cell) is controlled by more than one neuron, and the speed and power of the fiber's contractions depends on the combined effects of all its neurons. Vertebrates have a different system, in which one neuron controls a group of muscle fibers. Most annelids' longitudinal nerve trunks include giant axons (the output signal lines of nerve cells). Their large diameter decreases their resistance, which allows them to transmit signals exceptionally fast. This enables these worms to withdraw rapidly from danger by shortening their bodies. Experiments have shown that cutting the giant axons prevents this escape response but does not affect normal movement.

Question: What are giant axons?
Ans: the output signal lines of nerve cells

Article: In May 1970, the Revolutionary Intellectuals Seminar was held to bring intellectuals in line with the revolution, while that year's Legislative Review and Amendment united secular and religious law codes, introducing sharia into the legal system. Ruling by decree, the RCC maintained the monarchy's ban on political parties, in May 1970 banned trade unions, and in 1972 outlawed workers' strikes and suspended newspapers. In September 1971, Gaddafi resigned, claiming to be dissatisfied with the pace of reform, but returned to his position within a month. In February 1973, he resigned again, once more returning the following month.

Question: What did Gaddafi do in 1971?
Ans: In September 1971, Gaddafi resigned, claiming to be dissatisfied with the pace of reform, but returned to his position within a month.

Article: In their attempt to ensure white supremacy decades after emancipation, in the early 20th century, most southern states created laws based on the one-drop rule, defining as black, persons with any known African ancestry. This was a stricter interpretation than what had prevailed in the 19th century; it ignored the many mixed families in the state and went against commonly accepted social rules of judging a person by appearance and association. Some courts called it "the traceable amount rule." Anthropologists called it an example of a hypodescent rule, meaning that racially mixed persons were assigned the status of the socially subordinate group.

Question: What did some courts call the one-drop rule?
Ans:
"the traceable amount rule."