multi-level resource management

• 多级资源管理

multi-level resource management的用法和样例：

例句

1. Continue to define each level that you want to use in your multilevel list.
   继续定义要在多级列表中使用的每个级别。
2. With Multiple Level Undo you can safely experiment with various what-if scenarios.
   使用多级撤消可以安全地尝试各种假设分析方案。