proper operating condition

例句：

1. 1. The properoperating condition for this machine is to beoperated at a temperature of 20°C.
   这台机器的适当运行条件是温度为20°C。
2. 2.The company's new product line hasbeen designed to meet the proper operating conditionof modern consumers.
   该公司的新产品线已经设计成满足现代消费者的需求。
3. 3. Theproper operating condition for theplant was achieved by adjustingthe air flow rate.
   工厂达到适当的运行条件是通过调整空气流量实现的。