subalphabet

例句：

1. 1. The subalphabet system allows for easy access to information in a document.
   子字母表系统使得在文档中轻松访问信息变得容易。
2. 2. In the subalphabet, each letter has a corresponding number that can be used to reference it.
   在子字母表中，每个字母都有一个对应的数字，可以用来引用它。
3. 3. The subalphabet was designed to make it easier for people to read and write in languages with manycharacters.
   子字母表的设计目的是为了使人们更容易阅读和书写使用许多字符的语言。