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Author Question: It is important for students to learn to recognize common symbols such as , , or &, primarily so ... (Read 50 times) |
Multiple experimental evidences have confirmed that at the molecular level, cancer is caused by lesions in cellular DNA.
As the western states of America were settled, pioneers often had to drink rancid water from ponds and other sources. This often resulted in chronic diarrhea, causing many cases of dehydration and death that could have been avoided if clean water had been available.
There are more nerve cells in one human brain than there are stars in the Milky Way.
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.
The first documented use of surgical anesthesia in the United States was in Connecticut in 1844.