Nitrogen forms about 78% of the earth's atmosphere. 氮約占地球大氣的百分之七十八。
The Earth's atmosphere seeks a steady oxygen level much as a thermostat hones in on a steady temperature. 地球大氣尋求固定在某一氧含量水平，就像恒溫器總是尋求固定回某一溫度。
The earth's atmosphere filters out much of the sun's radiation. 地球大氣層可以濾掉太陽(yáng)的大部分射線(xiàn)。
Instead the Moon remains visible during totality, reflecting reddened light filtering into the Earth's shadow. 月全食期間月球還是可見(jiàn)，光線(xiàn)經(jīng)過(guò)地球大氣層散射到地球陰影里，讓月球反射出紅光。
