8.1 句子应该有多重不同的结构和长度
一个简单、重要的概念通常用短句子来表达。一个详细、复杂的说明则需要用较长的句子来解释。
8.2 避免散漫的句子
一般而言，一个句子只应表达一两个主要的观念，这样才能简单易懂。包含多个观念的句子，我们称之为散漫句。
8.3 避免连续的片段句子
it + v + 宾语，不断的重复类似的结构。
8.4 用对称的结构来表达对等的观念
wrong ex: the algorithm not only must avoid local maxima but also converge as quickly as possible.
right ex: the algorithm not only must avoid local maxima but also must converge as quickly as possible.
right ex: the algorithm must not only avoid local maxima but also converge as quickly as possible.
wrong ex: we will analyze the structure, computational complexity, and the performance of the algorithm.
right ex: we will analyze the structure, the computational complexity, and the performance of the algorithm.
right ex: we will analyze the structure, computational complexity, and performance of the algorithm.
分析：冠词只能放在第一个短语前面，否则所有的短语都得添加。
wrong ex: this interface is used for reading and writing to memory.
right ex: this interface is used for reading from and writing to memory.
分析： 不同的东西需要不同的介词
wrong ex: our aim is to identify the difficulties faced by customers who purchase these devices and develop more user-friendly products.
right ex: our aim is to identify the difficulties faced by customers who purchase these devices and to develop more user-friendly products.
分析：第一句中identity， purchase， develop三个动词放一起并列，这样会让人误解develop是修饰aim还是修饰who，因此在第二句中，我们为develop加了个to，这样其就与identify并列，句义就清晰了。
wrong ex: the experimental data confirm that the proposed method is accurate and fast algorithms based on this method can be implemented in practical applications.
right ex: the experimental data confirm that the proposed method is accurate and that fast algorithms based on this method can be implemented in practical applications.
分析：第一句初读的时候，感觉是在说提出的方法既精确又快，加个that之后，就将这层意思分开了。
8.5 用适当的对等结构与附属结构
bad ex: the dynamic Coulomb friction between two sliding surfaces always opposes the direction of motion and is given by the following expression.
good ex:the dynamic Coulomb friction between two sliding surfaces, which always opposes the direction of motion, could be expressed by the following equation.