只有当你熟悉单句后，才可以将句子连接起来。
方法1：如果两个简单句没有因果关系，基本上是两个独立的事情，往往可以简单地用and相连。
举例：Children are not sensitive to prices and parents prefer to satisfy their needs.
方法2：如果两个简单句有一定的因果关系，往往可以用状语从句相连。
一般来说，if 和when引导条件状语从句(也有一定因果关系，只是不那么强)
举例：If advertising campaigns directed at children are regulated, children will not pester their parents to buy many goods for them.
Since, as, because, so等引导原因或者结果状语从句，表示比较强的因果关系
举例：Some children like fast food since they are overwhelmed by fast food advertisements every day.
方法3：如果状语从句怕重复，可以用and(或者;)+连接词的方式
有很多连接词because of this, as a result of this, consequently, as a consequence 等，都是表示因果关系。
举例：Some children are addicted to violent video games, and because of this, they can show aggression and bully their peers at school.
方法4：如果第一个单句的最后一个单词和第二个单句的第一个单词重复，可以用定语从句连接。
举例：Children are increasingly temperamental due to their addiction to violent electronic games. These games are normally promoted by advertising firms.
可以改成：Children are increasingly temperamental due to their addiction to violent electronic games, which are normally promoted by advertising firms.
方法5：如果第二个单句是第一个单句的结果，有可能使用非限制性定语从句
举例：Advertisements have given a lot of information about products. This enables parents to make well-informed buying decisions.
可以改成：Advertisements have given a lot of information about products, which can help parents to make well-informed buying decisions.
简而言之，不要嫌弃简单句，简单句写熟了，复杂句很容易写。
