The following is a letter to the editor of an environmental magazine
The decline in the numbers of amphibians worldwide clearly indicates the global pollution of water and air. Two studies of amphibians in Yosemite National Park in California confirm my 妥泰能治癫痫吗conclusion. In 1915 there were seven species of amphibians in the park, and there were abundant numbers of each species. However, in 1992 there were only four species of amphibians observed in the park, and the numbers of each species were drastically reduced. The decline in Yosemite has been blamed on th平顶山癫痫病在哪治疗好e introduction of trout into the parks waters, which began in 1920 . But the introduction of trout cannot be the real reason for the Yosemite decline because it does not explain the worldwide decline.
In this argument, the writer of the letter conclude乌海癫痫病治好要多少钱s that global pollution of water and air has caused a decline in the number of amphibians worldwide. To support his or her conclusion, the writer cites the results of two studies, seventy-five years apart, that purportedly show that the number of amphibians in one park in California, Yosemite National Par羊角风怎么办k, have drastically declined. Additionally, the writer casts aside a given reason for the decline, stating that the introduction of trout to the park does not explain the worldwide decline in the number of amphibians. This argument defies simple logic and suffers from several critical fallacies.