次要系统

例句：

1. 1. The system for managing the data is complex and needs to be optimized.
   管理数据的系统复杂，需要优化。
2. 2. The secondary system of the city's transportation network is crucial for its efficiency.
   城市交通网络的次级系统对于其效率至关重要。
3. 3. The secondary system of the power grid can be disrupted by natural disasters.
   电网的次级系统可能会因自然灾害而受到干扰。