|
Author Question: Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + ... (Read 116 times) |
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
In the ancient and medieval periods, dysentery killed about ? of all babies before they reach 12 months of age. The disease was transferred through contaminated drinking water, because there was no way to adequately dispose of sewage, which contaminated the water.
Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.
The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).
Multiple experimental evidences have confirmed that at the molecular level, cancer is caused by lesions in cellular DNA.