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Approximately one in three babies in the United States is now delivered by cesarean section. The number of cesarean sections in the United States has risen 46% since 1996.
In 1864, the first barbiturate (barbituric acid) was synthesized.
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.
Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.
According to the National Institute of Environmental Health Sciences, lung disease is the third leading killer in the United States, responsible for one in seven deaths. It is the leading cause of death among infants under the age of one year.
![Massive amounts of wood are stored on the forest floor of old-growth temperate coniferous forests of](https://biology-forums.com/gallery/47/medium_33_28_08_11_12_01_59_1551376.jpeg)
![(a) Feeding by bear on salmon results in large allochthonous inputs of nutrients into (b) the forest](https://biology-forums.com/gallery/47/medium_33_17_02_12_7_02_16_2035460.jpeg)