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Author Question: Through trial and error, a rat learns to run a maze without mistakes to receive (Read 505 times) |
The highest suicide rate in the United States is among people ages 65 years and older. Almost 15% of people in this age group commit suicide every year.
Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.
Malaria was not eliminated in the United States until 1951. The term eliminated means that no new cases arise in a country for 3 years.
Interferon was scarce and expensive until 1980, when the interferon gene was inserted into bacteria using recombinant DNA technology, allowing for mass cultivation and purification from bacterial cultures.
In the United States, congenital cytomegalovirus causes one child to become disabled almost every hour. CMV is the leading preventable viral cause of development disability in newborns. These disabilities include hearing or vision loss, and cerebral palsy.