【托福写作】综合写作文本分析 TPO 10 阅读材料: The sea otter is a small mammal that lives in waters along the western coast of North America from California to Alaska. When some sea otter populations off the Alaskan coast started rapidly declining a few years ago, it caused much concern because sea otters play an important ecological role in the coastal ecosystem. Experts started investigating the cause of the decline and quickly realized that there were two possible explanations: environmental pollution or attacks by predators. Initially, the pollution hypothesis seemed the more likely of the two. 海獭是一种生活在北美西海岸从加州到阿拉斯加沿线的小型海洋哺乳动物。几年前, 阿拉斯加海岸的海獭数量急剧减少。由于海獭对于维持海岸沿线生态平衡有非常重要 的作用,所以其数量下降引起了广泛的关注。专家开始研究海獭数量下降的原因,并 且很快发现了两个可能的原因,分别是环境污染和天敌捕食。最初,环境污染说看起 来更为可信。 The first reason why pollution seemed the more likely cause was that there were known sources of it along the Alaskan coast, such as oil rings and other sources of industrial chemical pollution. Water samples from the area revealed increased levels of chemicals that could decrease the otters’ resistance to life-threatening infections and thus could indirectly cause their deaths. 为什么污染说更为可信呢?这是因为阿拉斯加海岸确实有污染源,比如石油带或者其 他的工业污染物。该地的水样显示水中化学物的含量增加,其数量可以导致海獭对于 对于一些致命感染丧失抵抗力,进而间接导致数量下降。 Second, other sea mammals such as seals and sea lions along the Alaskan coast were also declining; indicating that whatever had endangered the
