Breather valve and flame arrestor are indispensable safety devices.可见呼吸阀、阻火器是储罐不要缺少的安全设施.So the railroad will buy the spark arrestor.所以铁路将购买阻火器.The railroad will realize that it can save this $ 100 cost by investing $ 50...

arrestor的音标：arrestor的英式发音音标为：[ə'restə]arrestor的美式发音音标为：[ə'restə]...

n.被扣押的债务人财产的合法持有人...