fly-back line

But neutrinos fly in a straight line: Catch one, and you can trace it back to whatever produced it, which makes them one of the easiest means of probing the far reaches of the universe.

如果能捕捉到中微子的轨迹，那么就可以追溯出它的源头，而科学家们就经常使用这一方法来探测遥远的宇宙。

Perhaps one day, the line is broken, I just stood there, looking at the back of fly.

也许有一天，线断了，我呆呆地站在那里，看着飞离的背影。

I fly the aircraft back down to the 1,500-foot line at 500 feet and modify my airspeed to get at show center for the pullup. I level off at about 500 feet.

我在500英尺高度上把飞机飞回到1500英尺标线处，并且调整我的空速准备飞到展览中心上空时拉起，在大约500英尺标线处我把飞机改平。