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：Childrenare not sensitive to prices and parents prefer to satisfy their needs.

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：Ifadvertising campaigns directed at children are regulated, children will notpester 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：somechildren like fast food since they are overwhelmed by fast food advertisementsevery day.

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becauseof this, as a result of this, consequently, as a consequence等，都是表示因果关系。

举例：somechildren are addicted to violent video games, and because of this, they canshow aggression and bully their peers at school.

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：Childrenare increasingly temperamental due to their addiction to violent electronicgames. These games are normally promoted by advertising firms.

可以改成：Childrenare increasingly temperamental due to their addiction to violent electronicgames, which are normally promoted by advertising firms.

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：Advertisementshave given a lot of information about products. This enables parents to makewell-informed buying decisions.

可以改成：Advertisementshave given a lot of information about products, which can help parents to makewell-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。