secondary control

例句：

1. 1. The primary goal of the project is to improve efficiency.
   该项目的首要目标是提高效率。
2. 2.The secondary control measures were implemented as a result of the first round of testing.
   作为第一轮测试结果的次级控制措施被实施了。
3. 3. The team decided to implement a secondary control system to ensure safety during construction.
   团队决定实施一个次级控制系统以确保施工期间的安全。