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Author Question: It has become conventional to classify an economic downturn as a recession when aggregate output declines for (Read 22 times) |
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.
More than 50% of American adults have oral herpes, which is commonly known as "cold sores" or "fever blisters." The herpes virus can be active on the skin surface without showing any signs or causing any symptoms.
According to the National Institute of Environmental Health Sciences, lung disease is the third leading killer in the United States, responsible for one in seven deaths. It is the leading cause of death among infants under the age of one year.
Barbituric acid, the base material of barbiturates, was first synthesized in 1863 by Adolph von Bayer. His company later went on to synthesize aspirin for the first time, and Bayer aspirin is still a popular brand today.
In 1835 it was discovered that a disease of silkworms known as muscardine could be transferred from one silkworm to another, and was caused by a fungus.