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Author Question: You overhear two parents talking about the different approaches to teaching reading used by the ... (Read 89 times) |
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
Acute bronchitis is an inflammation of the breathing tubes (bronchi), which causes increased mucus production and other changes. It is usually caused by bacteria or viruses, can be serious in people who have pulmonary or cardiac diseases, and can lead to pneumonia.
Bacteria have been found alive in a lake buried one half mile under ice in Antarctica.
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.