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Author Question: Choose the letter (A, B, or C) that is followed by a sentence in which the underlined irregular verb ... (Read 26 times) |
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."
Drying your hands with a paper towel will reduce the bacterial count on your hands by 45–60%.
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.
Intradermal injections are somewhat difficult to correctly administer because the skin layers are so thin that it is easy to accidentally punch through to the deeper subcutaneous layer.