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Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
Everyone has one nostril that is larger than the other.
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.
A good example of polar molecules can be understood when trying to make a cake. If water and oil are required, they will not mix together. If you put them into a measuring cup, the oil will rise to the top while the water remains on the bottom.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.