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diff --git a/1000-hours/sounds-of-american-english/2.3.2-stress.md b/1000-hours/sounds-of-american-english/2.3.2-stress.md
index 6dd5f041..980297bb 100644
--- a/1000-hours/sounds-of-american-english/2.3.2-stress.md
+++ b/1000-hours/sounds-of-american-english/2.3.2-stress.md
@@ -51,7 +51,7 @@ Let's dig deep into the word *individual*, for example, it's pronounced as `/ˌ
 
 ![5-syllables-individual](/images/5-syllables-individual.svg)
 
-英文的元音有长短之分。需要注意的是：当一个**短元音**构成的**音节**是**重音**的时候，该音节会自然而然读得更长一些，比如 *city* 或者 *silly* 之中的第一个重音音节 `/ˈsɪ/` —— 可能是因为 `s` 音拉得更长；再比如，*Thanks, I owe you a big one.* 这句话里的 *big* —— 可能是因为 `bɪg` 这个词（**音节**）的**音调**（pitch, [3.5.1](3.5.1-pitch)）拉高，或者干脆是 `ɪ` 这个**短元音**拉长……
+英文的元音有长短之分。需要注意的是：当一个**短元音**构成的**音节**是**重音**的时候，该音节会自然而然读得更长一些，比如 *city* 或者 *silly* 之中的第一个重音音节 `/ˈsɪ/` —— 可能是因为 `s` 音拉得更长；再比如，*Thanks, I owe you a big one.* 这句话里的 *big* —— 可能是因为 `bɪg` 这个词（**音节**）的**音调**（pitch, [2.5.1](2.5.1-pitch)）拉高，或者干脆是 `ɪ` 这个**短元音**拉长……
 
 In English, vowel sounds can vary in length. It's interesting to note that when a syllable with a short vowel sound is *stressed*, it's naturally pronounced a bit longer. For example, the first stressed syllable in words like *city* or *silly*, `/ˈsɪ/` may be extended due to the drawn-out `s` sound. Similarly, the word *big* in the sentence "*Thanks, I owe you a big one*," may be elongated because the pitch of the syllable `bɪg` is raised or simply because the short vowel `ɪ` is stretched out.
 
diff --git a/1000-hours/sounds-of-american-english/2.4.3-cc.md b/1000-hours/sounds-of-american-english/2.4.3-cc.md
index b9797cc4..6a92adcd 100644
--- a/1000-hours/sounds-of-american-english/2.4.3-cc.md
+++ b/1000-hours/sounds-of-american-english/2.4.3-cc.md
@@ -6,9 +6,9 @@ The combination of "consonant + consonant" often requires more attention.
 
 ## 2.4.3.1 省音（elision）
 
-“**辅音 + 辅音**” 的组合，常常会造成前一个辅音虽然发声器官（*articulator*）动作完整但并不发声的情况，于是会出现一个既 “看不见” 也 “听不到” 的**停顿**（*stop*，[3.4.1](3.4.1-stop)），之前举过单词内存在这种情况的例子，*hotdog* 和 *network*，再比如，*hard-nosed*, *partner*……
+“**辅音 + 辅音**” 的组合，常常会造成前一个辅音虽然发声器官（*articulator*）动作完整但并不发声的情况，于是会出现一个既 “看不见” 也 “听不到” 的**停顿**（*stop*，[2.4.1](2.4.1-stop)），之前举过单词内存在这种情况的例子，*hotdog* 和 *network*，再比如，*hard-nosed*, *partner*……
 
-A "consonant + consonant" combination often results in an instance where the first consonant is articulated but not voiced, creating an *invisible and inaudible stop* (3.4.1). Examples of this within words include previously mentioned *hotdog* and *network*, as well as *hard-nosed*, *partner*, and so on.
+A "consonant + consonant" combination often results in an instance where the first consonant is articulated but not voiced, creating an *invisible and inaudible stop* ([2.4.1](2.4.1-stop)). Examples of this within words include previously mentioned *hotdog* and *network*, as well as *hard-nosed*, *partner*, and so on.
 
 有人把这种现象叫做 **省音**（*elision*）；但，这种说法容易产生误导，因为音的确是省了，但，动作却没省，不仅没有省，**动作还很完整**。
 
@@ -20,9 +20,9 @@ Within a meaning group, it's common for a word to end with a consonant and the f
 
 ## 2.4.3.2. 叠音（geminates）
 
-上一个音节末尾的辅音和下一个音节开头的辅音相同的时候，这一对相同的辅音被称作**叠音**（*geminates*）。在连贯的自然语音中，这两个辅音就只发声一次 —— 但听起来的时候，有可能感受到前一个辅音存在造成细微停顿。它从机制上来看，其实和**省音**（[3.4.3.1](3.4.3-cc#_3-4-3-1-省音-elision)）一样。其实哪怕相邻的两个辅音相似的时候，也会发生同样的现象。
+上一个音节末尾的辅音和下一个音节开头的辅音相同的时候，这一对相同的辅音被称作**叠音**（*geminates*）。在连贯的自然语音中，这两个辅音就只发声一次 —— 但听起来的时候，有可能感受到前一个辅音存在造成细微停顿。它从机制上来看，其实和**省音**（[2.4.3.1](2.4.3-cc#_2-4-3-1-省音-elision)）一样。其实哪怕相邻的两个辅音相似的时候，也会发生同样的现象。
 
-When the same consonant ends one syllable and begins the next, this pair of identical consonants is known as *geminates*. In fluid, natural speech, these two consonants are vocalized only once— yet, you might sense a slight *stop* due to the presence of the previous consonant, and its completion of articulating action. Mechanically, this is similar to *elision* ([3.4.3.1](3.4.3-cc#_3-4-3-1-省音-elision)). This phenomenon also occurs even when two neighboring consonants are just similar, not identical.
+When the same consonant ends one syllable and begins the next, this pair of identical consonants is known as *geminates*. In fluid, natural speech, these two consonants are vocalized only once— yet, you might sense a slight *stop* due to the presence of the previous consonant, and its completion of articulating action. Mechanically, this is similar to *elision* ([2.4.3.1](2.4.3-cc#_2-4-3-1-省音-elision)). This phenomenon also occurs even when two neighboring consonants are just similar, not identical.
 
 比如，*at that time*, 不是 `/ət ðæt taɪm/`，而是 `/ə·ðæt̬aɪm/` —— 第一个 `t` 由于后面跟着一个辅音，于是产生了**省音**，听不到了，但，该有的停顿却依然在，在这里我们用 `·` 代表那个停顿 ；而后，第二个 `t` 与第三个 `t` 是**叠音**，这两个 `t` 只发声一次。又比如，*a bad day*, 不是 `/ə bæd deɪ/`，而是 `/ə bæ·deɪ/`。 再比如，*with this*, 不是 `/wɪθ ðɪs/`，而是 `/wɪ·ðɪs/`。
 
@@ -37,9 +37,9 @@ Assimilation, in English pronunciation, primarily happens in two key scenarios:
 > * `t` + `j` = `tʃ`
 > * `d` + `j` = `dʒ`
 
-最常见的比如，*Don't you?* `/dəʊn tʃju?/`；以及，*Would you?* `/wʊ dʒju?/` 这里的关键在于，`t, d` 发声时起始的舌尖位置如果放对了（[3.2.3](3.2.3-td)），它与后面的 `/ju/` 连起来的发声就只能如此。
+最常见的比如，*Don't you?* `/dəʊn tʃju?/`；以及，*Would you?* `/wʊ dʒju?/` 这里的关键在于，`t, d` 发声时起始的舌尖位置如果放对了（[2.2.3](2.2.3-td)），它与后面的 `/ju/` 连起来的发声就只能如此。
 
-For example, in daily conversation, we often hear *Don't you?* pronounced as `/dəʊn tʃju?/`; and *Would you?* as `/wʊ dʒju?/`. The key here lies in the position of the tongue tip when pronouncing `t, d`. If placed correctly (as explained in [3.2.3](3.2.3-td)), it naturally leads to such pronunciation when followed by `/ju/`.
+For example, in daily conversation, we often hear *Don't you?* pronounced as `/dəʊn tʃju?/`; and *Would you?* as `/wʊ dʒju?/`. The key here lies in the position of the tongue tip when pronouncing `t, d`. If placed correctly (as explained in [2.2.3](2.2.3-td)), it naturally leads to such pronunciation when followed by `/ju/`.
 
 同化主要发生在 `j` 这个音上。除了已经讲过的 `j` 前面遇到 `t` 和 `d` 时会产生同化之外，
 
diff --git a/1000-hours/sounds-of-american-english/2.5-prosody.md b/1000-hours/sounds-of-american-english/2.5-prosody.md
index a735fb3d..df8a0139 100644
--- a/1000-hours/sounds-of-american-english/2.5-prosody.md
+++ b/1000-hours/sounds-of-american-english/2.5-prosody.md
@@ -7,15 +7,16 @@ Learning to speak is, in many ways, a simpler version of learning to sing. This
 歌曲是有韵律的，自然语音其实也一模一样…… 好听的歌声和好听的语音，简单说，总计需要注意以下几个方面：
 The prosody of speech is like the rhythm of a song. To make our speech or singing appealing to the ear, there are a few key elements we need to pay attention to. These are:
 
-> **高低**、**起伏**、**轻重**、**缓急**…… 以及，很多人并不重视的**停顿**（[3.4.1](3.4.1-stop)）。
-> *pitch*, *tone*, *emphasis*, *rhythm*, and oft-neglected *pauses*.
+> **高低**、**起伏**、**轻重**、**缓急**…… 以及，很多人并不重视的**停顿**（[2.4.1](2.4.1-stop)）。
+>
+> *pitch*, *tone*, *emphasis*, *rhythm*, and oft-neglected *pauses*([2.4.1](2.4.1-stop)).
 >
 > * **高低**指的是**音高**（*pitch*）的变化。
 > * *Pitch* refers to the high and low variations in voice.
 > * **起伏**指的是**声调**（*tone*），即，扬、平、降、轻。
 > * *tone* refers to the tone of voice, whether it's *rising*, *flat*, *falling*, or *light*.
-> * **轻重**（*stress*）落实到**音节**（就好像歌曲中的**音符**）上来看，就是轻重的安排，重音、次重音、非重音、弱音（[3.3.2](3.3.2-stress)）。
-> * *Stress* refers to the emphasis placed on a syllable, similar to the emphasis on a note in a song. There are various levels of stress such as *primary stress*, *secondary stress*, *unstressed*, and *weak schwa* ([3.3.2](3.3.2-stress)).
+> * **轻重**（*stress*）落实到**音节**（就好像歌曲中的**音符**）上来看，就是轻重的安排，重音、次重音、非重音、弱音（[2.3.2](2.3.2-stress)）。
+> * *Stress* refers to the emphasis placed on a syllable, similar to the emphasis on a note in a song. There are various levels of stress such as *primary stress*, *secondary stress*, *unstressed*, and *weak schwa* ([2.3.2](2.3.2-stress)).
 > * **缓急**（*rhythm*）由一组**音节**发声的速度构成 —— 在歌曲中，如果 4 个音符在同一个节拍里唱完，每个音符只占 $\frac{1}{4}$ 拍，那就每个音节都**很短**且**很快**；或者反过来，如果一个音符竟然持续了 2 个节拍，那就是这个音节**很长**，但**很慢**。
 > * *rhythm* is the speed at which a group of syllables is spoken. In a song, if four notes are sung in one beat, each note lasts a quarter of a beat, making each syllable short and fast. Conversely, if a single note spans two beats, the syllable is long and slow.
 
diff --git a/1000-hours/sounds-of-american-english/2.5.1-pitch.md b/1000-hours/sounds-of-american-english/2.5.1-pitch.md
index 13303cc2..373abdd2 100644
--- a/1000-hours/sounds-of-american-english/2.5.1-pitch.md
+++ b/1000-hours/sounds-of-american-english/2.5.1-pitch.md
@@ -22,9 +22,9 @@ If you can sing $\frac{4}{4}$ | 3 2 1 - | - indeed, anyone could sing these thre
 
 Then you can voice *fact*, *fact*, *fact*... in three different pitches, /fækt/(3) /fækt/(2) /fækt/(1-), and you will then feel the *pitch* changes in natural speech.
 
-**音高**（*pitch*）的控制，主要靠**喉部**（*larynx*）；而**语调**（*intonation*, [3.5.2](3.5.2-intonation)），由于涉及到音高的变化（**从高到低**或者**从低到高**），所以，也由喉部控制。如果有个人在我们面前讲话，在我们听到她声调明显变化的时候，就可以看得到她的喉咙部位的明显动作……[^1]
+**音高**（*pitch*）的控制，主要靠**喉部**（*larynx*）；而**声调**（*tone*, [2.5.2](2.5.2-tone)），由于涉及到音高的变化（**从高到低**或者**从低到高**），所以，也由喉部控制。如果有个人在我们面前讲话，在我们听到她声调明显变化的时候，就可以看得到她的喉咙部位的明显动作……[^1]
 
-Pitch control mainly relies on the *larynx*. *Intonation* (3.5.2), which involves pitch variation (from high to low or from low to high), is also controlled by the *larynx*. If someone is speaking in front of us, we can see the clear movement in their throat when we hear a noticeable change in their pitch...[^1]
+Pitch control mainly relies on the *larynx*. *tone* ([2.5.2](2.5.2-tone)), which involves pitch variation (from high to low or from low to high), is also controlled by the *larynx*. If someone is speaking in front of us, we can see the clear movement in their throat when we hear a noticeable change in their pitch...[^1]
 
 <video controls width="720"> <source src="/videos/CatherineAnderson.mp4" type="video/mp4"></source>Your browser does not support the video tag. </video>
 
diff --git a/1000-hours/sounds-of-american-english/2.5.3-emphasis.md b/1000-hours/sounds-of-american-english/2.5.3-emphasis.md
index 828b6621..8092fd1f 100644
--- a/1000-hours/sounds-of-american-english/2.5.3-emphasis.md
+++ b/1000-hours/sounds-of-american-english/2.5.3-emphasis.md
@@ -34,9 +34,9 @@ The same sentence, by *emphasizing* different *words*, can convey different mean
 > * Will you drive to the **office** tommorrow? (rather than somewhere else)
 > * Will you drive to the office **tommorrow**? (rather than some other day)
 
-被**强读**的词汇之中，重音音节往往带着**声调** —— 升、降、平、降升（[3.4](33-up-down)）。并且，少数重音音节会有被拔高的音高（[3.3](32-high-low)）。这些都是自然语流的韵律（*prosody*）格外重要的组成部分，也是跟读模仿时的重点之一。
+被**强读**的词汇之中，重音音节往往带着**声调** —— 升、降、平、降升（[2.5.2](2.5.2-tone)）。并且，少数重音音节会有被拔高的音高（[2.5.1](2.5.1-pitch)）。这些都是自然语流的韵律（*prosody*）格外重要的组成部分，也是跟读模仿时的重点之一。
 
-Stressed words often carry *tone* - *rising*, *falling*, *flat*, or *falling-rising*. Moreover, a few stressed syllables might have a higher *pitch*. These are significant parts of natural speech  *prosody*, and should be a focus when imitation reading.
+Stressed words often carry *tone* ([2.5.2](2.5.2-tone)) - *rising*, *falling*, *flat*, or *falling-rising*. Moreover, a few stressed syllables might have a higher *pitch*. These are significant parts of natural speech  *prosody*, and should be a focus when imitation reading.
 
 另外，除了少数词汇会被**强读** 之外，还会有很多词汇会被**弱读**。
 
@@ -95,18 +95,18 @@ If a word (or syllable) is *weakly pronounced*:
 > * Long vowels can get shorter (almost as short as short vowels);
 > * 重音音节会变得与非重音音节一样轻；
 > * The stressed syllable can be as light as the unstressed syllable;
-> * 很多元音都会发生变化，向 *schwa* `ə`（[3.1.2](3.1.2-ʌ)、[3.1.4](3.1.4-ə)）靠拢；
-> * Many vowels might change, moving towards *schwa* `ə` ([3.1.2](3.1.2-ʌ)、[3.1.4](3.1.4-ə));
-> * 很多与辅音相关的停顿（[3.4.1](3.4.1-stop), [3.4.3.1](3.4.3-cc#_3-4-3-1-省音-elision)）会被直接省略；
-> * Many stops or pauses ([3.4.1](3.4.1-stop), [3.4.3.1](3.4.3-cc#_3-4-3-1-省音-elision)) related to consonants can be directly omitted;
+> * 很多元音都会发生变化，向 *schwa* `ə`（[2.1.3](2.1.3-ʌ)、[2.1.5](2.1.5-ə)）靠拢；
+> * Many vowels might change, moving towards *schwa* `ə` ([2.1.3](2.1.3-ʌ)、[2.1.5](2.1.5-ə));
+> * 很多与辅音相关的停顿（[2.4.1](2.4.1-stop), [2.4.3.1](2.4.3-cc#_2-4-3-1-省音-elision)）会被直接省略；
+> * Many stops or pauses ([2.4.1](2.4.1-stop), [2.4.3.1](2.4.3-cc#_2-4-3-1-省音-elision)) related to consonants can be directly omitted;
 > * 清辅音 `s`、`t`、`k`、`f` 之后的元音 `ə` 可能会直接被省略掉；
 > * The vowel `ə` after `s`, `t`, `k`, `f` might be directly omitted;
 > * 整个单词所处的音高往往是 “高”、“中”、“低” 之中的 “低”，最多是 “中”……
 > * The whole word often has a *lower* pitch,  or at most *middle* pitch among *high*, *middle*, *low*.
 
-其实，哪怕在单独读某一个单词的时候，其中元音的长短都会受到重音重读的影响。比如，*city* 这个单词，重音在第一个音节上，而两处的元音是一样的：`/ˈsɪ-t̬ɪ/`；但是只要你把第一个音节读得足够重，自然而然就能感觉到**第一个音节**只能比**第二个音节**更长（[3.3.2](3.3.2-stress)）。
+其实，哪怕在单独读某一个单词的时候，其中元音的长短都会受到重音重读的影响。比如，*city* 这个单词，重音在第一个音节上，而两处的元音是一样的：`/ˈsɪ-t̬ɪ/`；但是只要你把第一个音节读得足够重，自然而然就能感觉到**第一个音节**只能比**第二个音节**更长（[2.3.2](2.3.2-stress)）。
 
-Actually, even when pronouncing a single word, the length of the vowels is influenced by the stress. For example, in the word *city*, the stress is on the first syllable, and both vowels are the same: `/ˈsɪ-t̬ɪ/`. But if you pronounce the first syllable heavy enough, you will naturally feel that the first syllable can only be longer than the second one ([3.3.2](3.3.2-stress)).
+Actually, even when pronouncing a single word, the length of the vowels is influenced by the stress. For example, in the word *city*, the stress is on the first syllable, and both vowels are the same: `/ˈsɪ-t̬ɪ/`. But if you pronounce the first syllable heavy enough, you will naturally feel that the first syllable can only be longer than the second one ([2.3.2](2.3.2-stress)).
 
 大多数助动词、系动词、介词、连词、冠词、代词，都有两种发音形式：**强读式**（*accented form*）、**弱读式**（*weak form*） —— 这些单词往往都是单音节单词。在自然语流中，它们更多的情况下是以**弱读式**读出的。以下是其中最常见的强读式、弱读式对照列表。注意，以下的列表不能当作硬规则使用，不是所有的虚词都必须被弱读；也不是所有的实词都必须被强读。下面的列表只是在描述现象。