closed delivery drill

例句：

1. 1. The company conducted a closed delivery drill to ensure the safety of its employees during the pandemic.
   该公司进行了一次闭路配送演练，以确保在疫情期间保障员工的安全。
2. 2. The closed delivery drill helped us identify potential risks and develop strategies to mitigatethem.
   这次封闭配送演练帮助我们识别了潜在的风险，并制定了相应的策略来减轻这些风险。
3. 3. During the closed delivery drill, we learned how to handle emergency situations and maintain order in a crisis.
   在这次封闭配送演练中，我们学习了如何应对紧急情况并保持危机中的秩序。