父亲解释说：“线不是阻止风筝飞得更高，而是帮助它在空中停留。”

The father explained, "The string was not stopping the kite from going higher, but was helping it stay in the sky."

youdao

激光瞄准安装在鹈鹕下面的光伏电池，给直升机的电池充电，使它在空中飞行了12小时27分钟。

The laser at photovoltaic cells mounted on the pelican's underside, charged the chopper's battery, keeping it aloft for 12 hours and 27 minutes.

youdao

撕下一张茫然的笑脸，它在空中盘旋。

An aimless smile that hovers in the air.

youdao

It goes up, stays in the air for a very long time, but it falls on your head.

它先上升 在空中停留很长时间,但是它会直接落在头上

耶鲁公开课 - 基础物理课程节选

That means, if you are going in a plane and you throw something up in the air, it seems to be going up and down to you.

也就是说,如果你在飞机中,你向空中扔出一物体,它也许会相对于你上下运动

耶鲁公开课 - 基础物理课程节选