几册的单词，common

是第五册的单词，意思是普通的，例如：

1、Breast cancer is the most common form of cancer among women in this country.乳腺癌是这个国家妇女中最常见的一种癌症。

2、The most common complaint is about poor service.最常见的投诉与服务差有关。

3、When did this word come into common use?这个词是什么时候普遍使用起来的