key module

例句：

1. 1.The key module of this system is responsible for data processing.
   该系统的关键模块负责数据处理。
2. 2. The development team identified the key module that needs to be improved.
   开发团队确定了需要改进的关键模块。
3. 3. The design of the software requires careful consideration of the key modules.
   软件设计需要仔细考虑关键模块。