Three tier structures

• 三层结构

Three tier structures的用法和样例：

例句

1. Pdf- Three structures and the module technology realize the staff data management system pdf.
   三层结构及组件技术实现员工数据管理系统。
2. The following code example shows how the site map might look for a simple site that goes three levels deep.
   下面的代码示例演示站点地图如何查找一个三层结构的简单站点。