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Author Question: Two equal masses are raised at constant velocity by ropes that run over pulleys, as shown below. ... (Read 9468 times) |
For about 100 years, scientists thought that peptic ulcers were caused by stress, spicy food, and alcohol. Later, researchers added stomach acid to the list of causes and began treating ulcers with antacids. Now it is known that peptic ulcers are predominantly caused by Helicobacter pylori, a spiral-shaped bacterium that normally exist in the stomach.
About 100 new prescription or over-the-counter drugs come into the U.S. market every year.
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.
A seasonal flu vaccine is the best way to reduce the chances you will get seasonal influenza and spread it to others.
Vaccines prevent between 2.5 and 4 million deaths every year.