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Author Question: Which of the following has emerged as one of the most pressing challenges of the early 21st century? (Read 159 times) |
Coca-Cola originally used coca leaves and caffeine from the African kola nut. It was advertised as a therapeutic agent and "pickerupper." Eventually, its formulation was changed, and the coca leaves were removed because of the effects of regulation on cocaine-related products.
Amoebae are the simplest type of protozoans, and are characterized by a feeding and dividing trophozoite stage that moves by temporary extensions called pseudopodia or false feet.
A recent study has found that following a diet rich in berries may slow down the aging process of the brain. This diet apparently helps to keep dopamine levels much higher than are seen in normal individuals who do not eat berries as a regular part of their diet as they enter their later years.
In the United States, there is a birth every 8 seconds, according to the U.S. Census Bureau's Population Clock.
Ether was used widely for surgeries but became less popular because of its flammability and its tendency to cause vomiting. In England, it was quickly replaced by chloroform, but this agent caused many deaths and lost popularity.