translation.en: Now before that mixture hits the patient's lungs, it's going to pass by here -- you can't see it, but there's an oxygen sensor here -- that's going to read out on this screen the percentage of oxygen being delivered.
translation.zh: 在混合气体 进入病人肺部之前 会先经过这里 你看不到，这是个氧气传感器－ 能读出氧气含量 显示在屏幕上