keep updated

1000-hours/sounds-of-american-english/2.1.2-tongue.md

@@ -10,8 +10,19 @@ The position of your tongue is crucial when pronouncing vowels. The following sh
 
 The position of your tongue in your mouth determines the size of the resonance space for airflow, which, when paired with different mouth shapes, produces various vowel sounds.
 
-虽然舍身位置很重要，但 “控制舍身位置” 对绝大多数人来说并不现实 —— 你试试就知道了。幸运的是，练习美式发音的时候，只有一种情况需要我们主动控制舍身位置并专门练习 —— `ə` 的儿化音（`ɚ` 和 `ɝː`），参见 [2.1.5](2.1.5-ə)。
+虽然舍身位置很重要，但 “控制舍身位置” 对绝大多数人来说并不现实 —— 你试试就知道了。
 
-While the position of the vocal cords is crucial, trying to consciously control it isn't realistic for most people - just give it a go and you'll see. Fortunately, when practicing American pronunciation, there's only one situation where we need to actively control and practice the position of the vocal cords - the r-colored vowel sound in `ə` (represented as `ɚ` and `ɝː`). Please refer to section [2.1.5](2.1.5-ə) for more information.
+While the position of the vocal cords is crucial, trying to consciously control it isn't realistic for most people - just give it a go and you'll see.
+
+以下是朗读一些单词的时候发声器官活动情况的 3D 展示[^2]：
+
+Here's a 3D illustration showcasing the activity of articulators when pronouncing certain words:
+
+<video controls width="720"> <source src="/videos/3d-presentation.mp4" type="video/mp4"></source>Your browser does not support the video tag. </video>
+
+幸运的是，练习美式发音的时候，只有一种情况需要我们主动控制舍身位置并专门练习 —— `ə` 的儿化音（`ɚ` 和 `ɝː`），参见 [2.1.5](2.1.5-ə)。
+
+Fortunately, when practicing American pronunciation, there's only one situation where we need to actively control and practice the position of the vocal cords - the r-colored vowel sound in `ə` (represented as `ɚ` and `ɝː`). Please refer to section [2.1.5](2.1.5-ə) for more information.
 
 [^1]: Figure adapted from *FUNDAMENTALS OF PHONETICS: a practical guide for students* 5th Edition, by Larry H. Small, 2019. Page 55
+[^2]: https://www.youtube.com/watch?v=wYwk07QM4rc