What goes up when rain goes down?

当下雨时什么东西却出现了。

But what goes up...must come down.

喷到天上的东西一定会掉下来。

You know what goes up must come down.

你知道既然上去就必须想办法下来。

What goes up everytime the rain comes down?

每次下雨后什么会上升？

So what is gravity? I bet most of you think it's: 'What goes up, must come down!' Is that right?

重力是什么？我想你们大多会想起：“向上移动的东西，一定会跌下来！”对吗？

But thanks to Isaac Newton, we know that what goes up must eventually come down.

但是伊萨克·牛顿让我们知道上升的东西总会下降。

Worried that what goes up might accidentally come down, the Djinns also gave the city particularly strong walls in the event that they come into premature contact with the ground.

考虑到仓促降落与地面的碰撞，灯神也赋予这座城镇尤为坚固的城墙，以免兴建的施设意外倒塌。