确实，这条轨迹还是跟曾经一样：笔直！然而现在它却铺满了岁月的碎石。

The path is straight as ever, but now it is strewn with the rocks and gravel that accumulate over a lifetime.

youdao

事实上，轨迹，简称为压缩痕迹，其本质上是云。他们跟大气层上自然形式的云没什么不同。

Actually, contrails, short for condensation trails, are essentially clouds. They are no different from the cirrus clouds that naturally form in that region of the atmosphere.

youdao

事实上，轨迹，简称为压缩痕迹，其本质上是云。他们跟大气层上自然形式的云没什么不同。

Actually, contrails, short for condensation trails, are essentially clouds. They are no different from the cirrus clouds that naturally form in that region of the atmosphere.

youdao