safety brake的用法和樣例：
例句
- Originally it was the safety valve for a hydraulic plant.
它最早是一家水電廠(chǎng)的安全閘閥。 - The safety gates at the railroad crossing are lowering.
鐵路交叉路口的安全閘正在放下來(lái)。 - Originally it was the safety valve for a hydraulic plant.
它最早是一家水電廠(chǎng)的安全閘閥。 - The safety gates at the railroad crossing are lowering.
鐵路交叉路口的安全閘正在放下來(lái)。
