.... stay above 80 degrees Fahrenheit year round. They can be found in 85 countries all over the world, however, 90 percent of them are concentrated into fifteen countries, each containing over ten million hectares. Tropical rainforests receive 160 to 400 inches of rain each year. Although these dense, damp forests cover just 5 percent of the Earth's surface, they can provide homes for between 50 and 90 percent of the Earth's plants and animals (http://www.davesite.com/rainforests/review1.shtml). Tropical rainforests consist of three distinct layers referred to as the .....

.... of antibiotics. There were so many different antibiotics developed that doctors and scientists focused their attention on other problems plaguing the nation. Doctors prescribed antibiotics frequently, often when they were not even needed. According to a 1998 report by the Institute of Medicine, up to fifty percent of antibiotics are prescribed unnecessarily. This blatant overuse of antibiotics had a profound effect on the efficiency of the drugs in the future. The wonder drugs that had been so effective in treating an array of diseases had started to lose the battle .....

.... were also found in sheep and livestock feed that was imported from Europe during this period. This new organism was introduced to a new habitat free from traditional parasites, predators and competitors, purple loosestrife thrived in the environmental conditions and by 1880 was rapidly spreading north and west through the canal and marine routes. Purple loosestrife stands also increased due to the importation of seeds and root stalks by horticulturists. It was introduced to many communities as an herb, an ornamental garden flower and as a desirable honey plant. One of the .....

.... of the tube back to the heart. The respiratory systems carries O2 to cells and takes away CO2 from cells through branching out to call cells of body. The nervous system consists of a brain receiving information from eyes, antennae, and controls the whole body and 2 nerve cords containing ganglia fused together to control activities of the segment without the help of the brain. insect muscular system is made up of a few thousand samll but string muscles allowing the insect to carry objects heavier than it. The digestive system is basically a long tube where food enters the m .....

.... experiments are done on animals. The thousands of animals put to suffer outweighs any of the research that has been gotten from them. Peter Singer the author of a piece called “Animal Experimentation” in the book Intervention and Reflection displays and evokes the actual suffering of many harmless animals. "In 1953 R. Soloman, L. Kamin, and L. Wynne, experimenters at Harvard University, placed forty dogs in a device called a 'shuttle box,' which consists of a box divided into two compartments, separated by a barrier. Initially the barrier was .....

.... of a basic model have been developed to highlight the way in which the written word is processed in the brain. The model is subdivided in to two main processing routes, the Non Lexical Route and the Lexical route. A model produced based on theories from Coltheart (1981) shows that there are several routes to speech production in the brain. The eye first identifies the printed word. In the adult skilled reader the eye does not move in a smooth pattern but actually jumps to certain focus points in a sentence the brain itself actually fills in the missing words. It does this by .....

.... hold back or control water flow. Dams are classified as either storage, diversion or detention. As you could probably notice from it's name, storage dams are created to collect or hold water for periods of time when there is a surplus supply. The water is then used when there is a lack of supply. For example many small dams impound water in the spring, for use in the summer dry months. Storage dams also supply a water supply, or an improved habitat for fish and wildlife; they may store water for hydroelectricity as well. A diversion dam is a generation of a commonly constru .....

.... a mild solution of sulfuric acid and nitric acid. These chemical reactions that change air pollution into acid rain can take from several hours to several days. Sunlight increases the rate of these reactions. Rainwater, snow, fog, and other forms of precipitation containing these mild solutions of sulfuric and nitric acids fall to the ground as acid rain. Years ago, when smokestacks were only a few stories tall, pollution from the smokestacks usually stayed near the ground and settled on the land nearby. This only caused unhealthy conditions for plants and animals near th .....