go-ahead
行信号放大器 [电子] line amplifier
检票员等待着信号准备开锁，收铁门，放行，乘客们咬着牙、卯足劲，因为一旦门开，就是疯狂的冲锋。
As attendants wait the signal to unlock and roll back the steel, passengers chomp a little bit. It's a mad dash once the gate is open.
youdao
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模块上移
模块下移
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