passage

　　the intelligence of dolphins is well documented by science. studies show that dolphins are able to understand sign language, solve puzzles, and use objects in their environment as tools. scientists also believe that dolphins possess a sophisticated language: numerous instances have been recorded in which dolphins transmitted information from one individual to another. a recent experiment proved that dolphins can even recognize themselves in a mirror something achieved by very few animals. this behavior demonstrates that dolphins are aware of their own individuality, indicating a level of intelligence that may be very near our own.

　　解析：

　　我们说，说明文是介绍一个事物。也可能是一个新事物，就像这篇关于海豚智商的报道。它说：“海豚的智商用科学的方法很好地记录下来了。”这是一个topic sentence,如同是一个文章的议论文的主题或是记叙文背景，规范了文章或是短论的内容和逻辑范畴。

　　在这里，通过第一句我们知道这里所要涉及的是海豚的智商，而且，也明确地告知，所讲述的内容是科学方法记录海豚智商。这里的重点是科学方法。什么是科学方法是读者关心的问题。

　　首先，什么是“科学”?在广义上说科学是一个过程或是一种方法，如：“科学”=“critical 思维”+“实验”+“观察”。当然，组成科学的这三部分的先后顺序倒是无所谓。正如下面这个文章结构：

　　topic sentence:

　　the intelligence of dolphins is well documented by science.

　　first 观察揭示：

　　studies show that dolphins are able to understand sign language, solve puzzles, and use objects in their environment as tools.

　　second 科学家相信：

　　scientists also believe that dolphins possess a sophisticated language: numerous instances have been recorded in which dolphins transmitted information from one individual to another.

　　third 实验证明：

　　a recent experiment proved that dolphins can even recognize themselves in a mirror something achieved by very few animals. this behavior demonstrates that dolphins are aware of their own individuality.

　　结果是海豚的智商和我们人类差不多：

　　those facts indicated a level of intelligence of dolphins that may be very near our own.

　　首先，我们发现，如果你对“科学”一词理解正确，那么，studies show, scientist believe, and experiment prove 这三句的出现就是理所当然 anticipated answers。

　　进一步，如同在上面所做加工，再完善一下，我们完全可以把一个段落改写成一个文章。而且结构几乎是完全对称。这便是英文写作强调的一种几何美。