At low oxygen concentrations, unconsciousness and death may occur in seconds and without warning.
At low oxygen concentrations, unconsciousness and death may occur in seconds and without warning.
在低氧浓度情况下，意识不清和死亡会在几秒钟内发生，而且没有警告。
At low oxygen concentrations, unconsciousness and death may occur in seconds and without warning.
在低氧浓度情况下，意识不清和死亡会在几秒钟内发生，而且没有警告。