例子：例子必出题。文章有论点-论据-论证，例子是论证，用来支持论点，所以简而言之，例子本身不重要，但前后论点极其重要。
例子开始的标志：for example，后面跟着大写、时间、年代，依然是举例内容。
例子含义的标志：show， tell， prove， demonstrate， find， clearly
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In the United States， the need to protect plant and animal species has become a highly controversial and sharply political issue since the passage of the Endangered Species Act in 1973. The act， designed to protect species living areas， and policies that preserve land and forests compete with economic interests. In the 1990 s， for example， the woodcutters in the Western United States were challenged legally in their attempt to cut trees for timber in the Cascade Mountains. The challenge was mounted to protect the endangered spotted owl(猫头鹰)， whose remaining population occupies these forests and requires the intact， ancient forest for survival. The problematic situation set the interests of environmentalists against those of corporations and of individuals who stood to lose jobs. After months of debate and legal battles， the fate of the woodcutters-and the owls-was still undecided in mid-1992.
注：1. controversial的意思是受争议的，同 sharply political issue ，contro表示 反
2. for example前句子是重点
3. problematic悬而未决的
Similar tensions exist between the developed and the developing nations. Many people in industrialized nations， for example， believe that developing nations in tropical regions should do more to protect their rain forests and other natural areas. But the developing countries may be impoverished (使穷困)， with populations growing so rapidly that using the land is a means to temporarily avoid worsening poverty and starvation.
注：1. tension张力，冲突
2. 看到similar就说明第二段说的和第一段一样。
3. But转折是重点
Many of the changes to Earth that concern scientists have the potential to rob the planet of its biological richness. The destruction of Earth s ozone layer (臭氧层)， for example， could contribute to the general process of impoverishment by allowing ultra-violet rays to harm plants and animals. And global warming could wipe out species unable to quickly adapt to changing climates. Clearly， protecting will come only through coordinated international efforts to control human population， stabilize the composition of the atmosphere， and preserve intact Earth s complex web life.