keep updated

1000-hours/sounds-of-american-english/2.4.1-stop.md

@@ -45,9 +45,26 @@ Regardless of the type, most of such stops occur when a previous consonant is fu
 
 Apart from *stops*, a sentence can be divided into several *meaning groups*, each separated by an obvious *pause*.
 
-比如，*I don't think I've got any milk left*<span class="speak-word-inline" data-audio-us-male="/audios/us/sentence-don't-think-i-alloy.mp3" data-audio-us-female="/audios/us/sentence-don't-think-i-nova.mp3"></span>. 这句话显然会被分割为至少两个**意群**：*I don't think* | *I've got any milk left*. 因为两个意群之间有**暂停**，所以 *think* `/θɪŋk/` 末尾的 `k` 不会与后面的只有一个元音的单音节词汇 *I* `/aɪ/` 连在一起。另外，请注意这里的 *milk* —— 这个词你专门练过 —— 它末尾的 `k` 是个**喉塞音**……
+先听听这段话的录音[^1]：
 
-For example, the sentence "*I don't think I've got any milk left.*"<span class="speak-word-inline" data-audio-us-male="/audios/us/sentence-don't-think-i-alloy.mp3" data-audio-us-female="/audios/us/sentence-don't-think-i-nova.mp3"></span> would likely be split into two meaning groups: "*I don't think*" and "*I've got any milk left.*" Because there's a *pause* between these groups, the `k` at the end of *think* doesn't connect with the following monosyllabic word *I*. Additionally, note the word *milk* - a word you've intensely practiced before - at the end, where there's a *glottal stop* with the `k` sound.
+Check out the recording of this stentence:
+
+> *Yet, it is a fact of life that an unlettered peasant is considered ignorant.* <span class="speak-word-inline" data-audio-us-male="/audios/us/yet-it-is-a-fact.mp3"></span>
+>
+> 以下是这段音频的 *Waveform*（波谱）和 *Pitch Contour*（音高变化）：
+>
+> Here are the Waveform and Pitch Contour for this audio clip:
+>
+> ![yet-it-is-a-fact-of-life](/images/yet-it-is-a-fact-of-life.png)
+>
+> * *Pitch Contour* 截图来自学习辅助工具 [Enjoy](https://github.com/xiaolai/everyone-can-use-english)。
+> * The screenshot of the Pitch Contour is from the learning aid App [Enjoy](https://github.com/xiaolai/everyone-can-use-english).
+
+在 Waveform 里我们可以清楚地看到，这句话里有两处明显的停顿（用 `|` 标注）：
+
+In the Waveform, we can clearly see two significant pauses (marked with `|`) in this sentence:
+
+> *Yet, | it is a fact of life | that an unlettered peasant is considered ignorant.* <span class="speak-word-inline" data-audio-us-male="/audios/us/yet-it-is-a-fact.mp3"></span>
 
 **停顿**（*stop*）与**暂停**（*pause*）可以用**可否换气**进行区分：
 
@@ -57,3 +74,5 @@ The distinction between *stop* and *pause* can be clarified by whether or not on
 > * A *stop* usually occurs between syllables where you don't need to, and often can't, take a breath;
 > * 意群之间的**暂停**（*pause*）是可以换气的 —— 当然若非必要也可以不换气；
 > * A *pause* typically happens between meaning groups, where you have the opportunity to take a breath - although it's not always necessary to do so.
+
+[^1]: This audio clip is extracted from the Audible edition of *Knowledge and Decisions* by Thomas Sowell.

1000-hours/sounds-of-american-english/2.4.2-cv.md

@@ -12,13 +12,13 @@ For instance, when saying *People's opinions vary from individual to individual*
 
 There are two particular types which are quite challenging and require deliberate practice. These involve the use of `t` and `l`, respectively.
 
-在美式英语里，`t` 有个特殊的现象，它夹在两个元音之间的时候会被浊化，被读成弹舌音，用 `t̬` 表示，听起来接近 `d`…… 比如，在 city `/ˈsɪt̬i/` 这个词汇里， `t` 就夹在两个元音之间。
+之前提到过，在美式英语里，`t` 有个特殊的现象，它夹在两个元音之间的时候会被浊化，被读成弹舌音，用 `t̬` 表示，听起来接近 `d`…… 比如，在 city `/ˈsɪt̬i/`<span class="speak-word-inline" data-audio-us-male="/audios/us/city-us-male.mp3" data-audio-us-female="/audios/us/city-us-female.mp3"></span> 这个词汇里， `t` 就夹在两个元音之间。
 
-In American English, the `t` sound has a unique characteristic. When it's sandwiched between two vowels, it's often voiced with an *alveolar flapping*, creating a sound very close to `d`. This is represented as `t̬`. For example, in the word *city* `/ˈsɪt̬i`/, the `t` is between two vowels.
+It is previously mentioned that in American English, the `t` sound has a unique characteristic. When it's sandwiched between two vowels, it's often voiced with an *alveolar flapping*, creating a sound very close to `d`. This is represented as `t̬`. For example, in the word *city* `/ˈsɪt̬i`/<span class="speak-word-inline" data-audio-us-male="/audios/us/city-us-male.mp3" data-audio-us-female="/audios/us/city-us-female.mp3"></span>, the `t` is between two vowels.
 
-在自然语流里，同一个意群中，经常会出现以 `t` 结尾的词汇后面跟着一个以元音开头的词汇，并且，`t` 的前面是元音的概率也很高，所以，词汇之间出现 `t` 的浊化弹舌音 `t̬` 的情况非常普遍。
+在自然语流里，同一个意群中，经常会出现以 `t` 结尾的词汇后面跟着一个以元音开头的词汇，并且，`t` 的前面是元音的概率也很高，所以，词汇之间出现 `t` 的浊化弹舌音 `t̬` 的情况非常普遍。比如，*Get it done.* `/ɡet̬ ɪt dʌn/`<span class="speak-word-inline" data-audio-us-male="/audios/us/sentence-it-done-alloy.mp3" data-audio-us-female="/audios/us/sentence-it-done-nova.mp3"></span>
 
-In natural speech flow, it's common to find a word ending with `t` closely followed by a word beginning with a vowel within the same meaning group. Furthermore, there's a high possibility that the `t` is preceded by a vowel. Therefore, the occurrence of the flapped `t̬` between words is incredibly prevalent.
+In natural speech flow, it's common to find a word ending with `t` closely followed by a word beginning with a vowel within the same meaning group. Furthermore, there's a high possibility that the `t` is preceded by a vowel. Therefore, the occurrence of the flapped `t̬` between words is incredibly prevalent. For example: *Get it done.* `/ɡet̬ ɪt dʌn/`<span class="speak-word-inline" data-audio-us-male="/audios/us/sentence-it-done-alloy.mp3" data-audio-us-female="/audios/us/sentence-it-done-nova.mp3"></span>
 
 `l` 构成的连读，对绝大多数人来说，难点在于，如果前一个单词末尾的 `l` **舌尖动作不够完整**的话（即，结束的时候舌尖没有贴到龈脊）那么，`l` 这个弹舌音就发不出来，无法与后面的元音连上…… 尤其是在没有纠正掉用嘴唇动作替代舌尖动作的错误（乃至于有 `ʊ` 的音色）的情况下。