前段时间为gre考生汇总了gre issue写作提纲思路和分析，希望对考生在攻破gre issue写作上有所帮助。接下来的几天我们将为gre考生整理gre argument部分的提纲内容。希望通过我们的整理和汇总，让gre考生真正能掌握gre写作的精髓。

　　题目题材：动物，环境

　　gre argument 207题目：

　　It is known that in recent years, industrial pollution has caused the Earths ozone layer to thin, allowing an increase in the amount of ultraviolet radiation that reaches the Earths surface. At the same time, scientists have discovered, the population of a species of salamander that lays its eggs in mountain lakes has declined. Since ultraviolet radiation is known to be damaging to delicate tissues and since salamander eggs have no protective shells, it must be the case that the increase in ultraviolet radiation has damaged many salamander eggs and prevented them from hatching. This process will no doubt cause population declines in other species, just as it has in the salamander species .

　　提纲：

　　The scientists only studied the population of salamanders at one certain cite, thus we could not assert that the overall salamander population is declining.

　　The author fails to compare the populations of other species of salamander whose eggs are not affected by ultraviolet radiation.

　　The author fails to rule out other possible factors that could result in the decline in the population of the salamander species.

　　We could not hastily generalize that other species will also be affected by the process merely based on the decline in the population of certain salamander species.

　　注：题目中括号里的数字表明这句话体现的是提纲中第几号缺陷。

　　无论是gre issue还是gre argument，考生都应该养成写提纲的习惯。这种提纲式的gre写作练习可以帮助考生锻炼写作的逻辑性，而gre写作高分最重要的得分依据就是作文的逻辑性要强。

　　前段时间为gre考生汇总了gre issue写作提纲思路和分析，希望对考生在攻破gre issue写作上有所帮助。接下来的几天我们将为gre考生整理gre argument部分的提纲内容。希望通过我们的整理和汇总，让gre考生真正能掌握gre写作的精髓。

　　题目题材：动物，环境

　　gre argument 207题目：

　　It is known that in recent years, industrial pollution has caused the Earths ozone layer to thin, allowing an increase in the amount of ultraviolet radiation that reaches the Earths surface. At the same time, scientists have discovered, the population of a species of salamander that lays its eggs in mountain lakes has declined. Since ultraviolet radiation is known to be damaging to delicate tissues and since salamander eggs have no protective shells, it must be the case that the increase in ultraviolet radiation has damaged many salamander eggs and prevented them from hatching. This process will no doubt cause population declines in other species, just as it has in the salamander species .

　　提纲：

　　The scientists only studied the population of salamanders at one certain cite, thus we could not assert that the overall salamander population is declining.

　　The author fails to compare the populations of other species of salamander whose eggs are not affected by ultraviolet radiation.

　　The author fails to rule out other possible factors that could result in the decline in the population of the salamander species.

　　We could not hastily generalize that other species will also be affected by the process merely based on the decline in the population of certain salamander species.

　　注：题目中括号里的数字表明这句话体现的是提纲中第几号缺陷。

　　无论是gre issue还是gre argument，考生都应该养成写提纲的习惯。这种提纲式的gre写作练习可以帮助考生锻炼写作的逻辑性，而gre写作高分最重要的得分依据就是作文的逻辑性要强。