词汇	button-head spring
释义	button-head spring 钮头弹簧
随便看	underground obstruction underground office underground of mine underground of reinforced concrete storeroom underground oil depot underground oil depot survey Underground oil-pipeline Underground oil pipelines underground oil reservoir underground oil storage underground opening underground openings underground openings and tunnels underground open space underground operation underground ore body Underground or elevated train driver Underground ore unloading station underground organization underground orientation survey underground or underwater installation underground or underwater SIPHON underground or underwater SIPHONS underground packing garage Underground Packing System