level of net

例句：

1. 1. The students are at different levels of understanding the material.
   学生们对材料的理解程度各不相同。
2. 2. The company has different levels of management for its employees.
   公司为员工设置了不同的管理层级。
3. 3. The level of difficulty in this problem is quite high.
   这个问题的难度相当高。