He says they actually use dental floss to slowly saw away at the metal, adding tooth powder to increase the friction.

但是犯人们总能找到办法弄到。现在他们用牙线慢慢钜金属，抹上牙粉增加摩擦力。

youdao

So you saw in a striking example of where friction helped us to balance, and now I want to discuss an object that is hanging and that can freely swing due to gravity.

这就是著名的靠，摩擦力平衡的例子，现在我想讨论一个，可以在重力作用下，自由摆动的悬挂物体。

youdao