Therefore, this thesis makes a research on the route planning method of low observable aircraft.

为此本文研究了低可观测飞行器的航迹规划方法。

youdao

Mars is too faint and too low in the sky to be observable.

火星太暗，在空中位置太低，所以观测不到。

《柯林斯英汉双解大词典》

Mars is too faint and too low in the sky to be observable.

火星太暗，在空中位置太低，所以观测不到。

《柯林斯英汉双解大词典》