|
Author Question: A company manufacturing computer chips finds that 8% of all chips manufactured are defective. ... (Read 110 times) |
Asthma is the most common chronic childhood disease in the world. Most children who develop asthma have symptoms before they are 5 years old.
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.
Ether was used widely for surgeries but became less popular because of its flammability and its tendency to cause vomiting. In England, it was quickly replaced by chloroform, but this agent caused many deaths and lost popularity.
The Romans did not use numerals to indicate fractions but instead used words to indicate parts of a whole.
In 1844, Charles Goodyear obtained the first patent for a rubber condom.