Fricative are often a source of confusion for English learners.

摩擦让很多英语学习者感到困惑。

To be clear, fricatives mean there is a partial obstruction in the air stream.

清楚地说，摩擦指的是气流有部分被阻滞。

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

这些都是摩擦，声慢慢地出你会听到摩擦声。

And finally, the vociceless fricative or be quiet sound, shhhhhh, present in words such as shower and push.

最后是清擦或“安静”，出现在诸如 shower 和 push 等词。

In a previous video, we explored the two affricates, or complex consonant sounds, of American English.

在之前的个视频里，我们探索了美式英语的两个破擦，或者叫复杂辅。

Affricates are made up of a stop sound followed by a fricative sound.

破擦由个爆破和后面的擦组成。

In a previous video, I described affricates as being kind of like addition - one plus one equals two.

在之前的个视频里，我说破擦有点像加法 —— 加等于二。

Another way to think of this is stop sound plus fricative sound equals affricate.

个思考的方法是爆破加上擦等于破擦。

In today's program, we will explore fricatives.

在今天的节目里，我们要探索摩擦。

Another type of consonant is a Fricative.

种辅是摩擦。

The English alveolar approximant, the Spanish trill, the French uvular fricative?

英国的齿槽、西班牙的颤、法国的小舌擦？

Next are the fricatives, where two parts touch.

接下来是摩擦，其两个部位接触。

You can put another sibilant in front of that if you want.

如果你想的话，可以在前面再加个齿擦。

In some cases, voiceless fricatives began to be pronounced like an " f" (e.g. laugh, cough).

在某些情况下，清擦开始像“f”样（例如笑、咳嗽）。

So the combination d-g sound, " dg" is an affricate in American English for judge becomes " j" .

所以在美式英语， 组合d-g“dg” 会变成个塞擦， 在单词judge变为“j” 。

So fff, and vvv are fricatives.

所以 fff 和 vvv 是擦。

Sss, zzz are fricatives. Thh, vvv are Fricatives too.

Sss, zzz 是擦。 Thh, vvv 也是擦。

The rule reads: a voiced fricative is transformed into the corresponding voiceless sound when it appears before a voiceless sound.

规则如下：浊摩擦出现在清之前时， 将转换为相应的清。

First, when the thickened layers of the pericardium rub up against each other - it creates a friction rub which can be heard on auscultation.

当增厚的两层心包膜互相摩擦，可在听诊时闻及心包摩擦。

It usually results in a friction rub, as well as ECG changes like ST elevation and PR depression, followed by T wave flattening and inversion.

通常表现出心包摩擦，以及ST段抬高和PR段压低等心电图改变，继之呈现T波低平和倒置。