manually operated valve造句

例句与造句

1. Manually operated valves for natural gas dispensing systems
   天然气分装系统手动控制阀
2. Most are manually operated valves ( by hand ) or mechanically controlled ( pressure / vacuum or float level )
   大部分为手动阀门或机械控制阀（压力/真空或浮子度） 。
3. It's difficult to find manually operated valve in a sentence. 用manually operated valve造句挺难的