Paragraphs
本单元提供了一些如何构建连贯段落的要点。先参考如下启发性的信息：
写作工作不过就是理清主题各部分间的依赖关系，并按照一定的逻辑顺序将这些内容呈现给读者，使读者能够理解你。
写好段首句
段首句是每个段落最重要的句子。忙碌的读者会专注于段首句而有时会跳过其余的句子。因此，请将你的写作精力集中在段首句上。
好的首句会点出段落的核心观点。例如，以下段落就有一个有效的首句:
A loop runs the same block of code multiple times. For example, suppose you wrote a block of code that detected whether an input line ended with a period. To evaluate a million input lines, create a loop that runs a million times.
上述段落的首句将段落的主题确立为对循环的介绍。相比之下，如下段首句则将读者引向了错误的方向：
A block of code is any set of contiguous code within the same function. For example, suppose you wrote a block of code that detected whether an input line ended with a period. To evaluate a million input lines, create a loop that runs a million times.
练习
如下段落的首句是有效的还是有缺陷的？
The Pythagorean Theorem states that the sum of the squares of both legs of a right triangle is equal to the square of the hypotenuse. The k-means clustering algorithm relies on the Pythagorean Theorem to measure distances. By contrast, the k-median clustering algorithm relies on the Manhattan Distance.
该段首句是有缺陷的，因为其暗示着段落将专注于介绍勾股定理（毕达哥拉斯定理）。但实际上，该段重点是介绍聚类算法。如下则是一个更有效的首句：
Different clustering algorithms measure distances differently.
每段专注一个主题
一个段落应该代表一个独立的逻辑单元。将每个段落限制在当前主题上，而不要描述为未来或过去的主题是什么。修改时，可以简单粗暴地删掉任何与当前主题不直接相关的句子（或将其移至其他段落）。
例如，假设如下段落的首句有专注正确的主题。你能找出应该从下一段中删除的句子吗？
The Pythagorean Theorem states that the sum of the squares of both legs of a right triangle is equal to the square of the hypotenuse. The perimeter of a triangle is equal to the sum of the three sides. You can use the Pythagorean Theorem to measure diagonal distances. For example, if you know the length and width of a ping-pong table, you can use the Pythagorean Theorem to determine the diagonal distance. To calculate the perimeter of the ping-pong table, sum the length and the width, and then multiply that sum by 2.
我们删除了第二句和第五句，以产生一个专注于勾股定理的段落。
The Pythagorean Theorem states that the sum of the squares of both legs of a right triangle is equal to the square of the hypotenuse.
The perimeter of a triangle is equal to the sum of the three sides.You can use the Pythagorean Theorem to measure diagonal distances. For example, if you know the length and width of a ping-pong table, you can use the Pythagorean Theorem to determine the diagonal distance.To calculate the perimeter of the ping-pong table, sum the length and the width, and then multiply that sum by 2.
练习
将下面段落中无关的句子移除（假设段首句确实为段落建立了所需的主题）:
Spreadsheets provide a great way to organize data. Think of a spreadsheet as a table with rows and columns. Spreadsheets also provide mathematical functions, such as means and standard deviations. Each row holds details about one entity. Each column holds details about a particular parameter. For example, you can create a spreadsheet to organize data about different trees. Each row would represent a different type of tree. Each column would represent a different characteristic, such as the tree's height or the tree's spread.
该段落侧重于将电子表格作为一种组织数据的方式，但第三句话与主题有所偏离。将第三句移到关于电子表格数学运算的段落中会更好：
Spreadsheets provide a great way to organize data. Think of a spreadsheet as a table with rows and columns.
Spreadsheets also provide mathematical functions, such as means and standard deviations.Each row holds details about one entity. Each column holds details about a particular parameter. For example, you can create a spreadsheet to organize data about different trees. Each row would represent a different type of tree. Each column would represent a different characteristic, such as the tree's height or the tree's spread.%/accordion%
段落不宜过长或过短
长段落在视觉上令人望而生畏。超长的段落变成是令读者忽略的可怕“文字墙”。读者普遍欢迎包含三到五个句子的段落，但会避免包含大约7个句子的段落。修改时，可以将很长的段落分成两个单独的段落。
相反地，也不要让段落过短。文档中包含大量的单句段落，代表文档的组织是有缺陷的。请找到方法将这些短句段落组合成有凝聚力的多句段落或者列表。
回答what, why和how
好的段落能回答以下三个问题：
- 你想告诉读者什么（What are you trying to tell your reader）?
- 为什么读者需要知道这些（Why is it important for the reader to know this）?
- 读者该如何利用这些知识，或读者怎么知道你的观点是正确的（How should the reader use this knowledge? Alternatively, how should the reader know your point to be true）?
例如，如下段落就回答了 what, why和how：
<Start of What>The
garp()function returns the delta between a dataset's mean and median.Many people believe unquestioningly that a mean always holds the truth. However, a mean is easily influenced by a few very large or very small data points. Call garp()to help determine whether a few very large or very small data points are influencing the mean too much. A relatively smallgarp()value suggests that the mean is more meaningful than when thegarp()value is relatively high.
Reference
原文: https://developers.google.com/tech-writing/one/paragraphs