S, creating this really tense friction sound.

/s/，产生了非常紧张的摩擦声。

These are all fricatives, the sounds are coming out slowly and you hear this friction sound.

这些都是摩擦音，声音慢慢地发出你会听到摩擦声。

You have this friction sound and you feel the vibration, and it's tickling a little bit.

你会听到摩擦的声音，你会感觉到振动，它会有点痒。

You're releasing air with sound, so the vocal cords are vibrating and creating this friction sound which is the 'V' as of the word 'very', 'vicious' and 'seven'.

是要通过释放口腔里的空气带动发音的，所以声带是振动的，产生出这种擦音，即‘V’，比如单词‘very’、‘vicious’和‘seven’。

So, to make the th sound you already know, I hope that the tongue needs to be outside, and the air has to pass between the tongue and teeth in order to create this friction sound.

所以，要发出你已经知道的 th 音，需要舌头在外面，空气必须通过舌头和牙齿之间，才能发出摩擦音。