If you look at what happened -- this little black line is as fast as man ever flew, and the red line is top-of-the-line military fighters and the blue line is commercial air transport.
如果你看一看发生了什么 -- 这条小黑线和人们曾经飞行的速度一样快， 这条红线代表军队里速度最快的飞行员 蓝色代表商业飞机运输。