diff --git a/app/difficulty.py b/app/difficulty.py
index 8179c57..cb93768 100644
--- a/app/difficulty.py
+++ b/app/difficulty.py
@@ -48,16 +48,19 @@ def get_difficulty_level_for_user(d1, d2):
     d1 用户不会的词
     在d2的后面添加单词，没有新建一个新的字典
     """
+    # TODO: convert_test_type_to_difficulty_level() should not be called every time.  Each word's difficulty level should be pre-computed.
     d2 = convert_test_type_to_difficulty_level(d2)  # 根据d2的标记评级{'apple': 4, 'abandon': 4, ...}
-    stem = snowballstemmer.stemmer('english')
+    stemmer = snowballstemmer.stemmer('english')
 
     for k in d1:  # 用户的词
         if k in d2:  # 如果用户的词以原型的形式存在于词库d2中
             continue  # 无需评级，跳过
-        elif stem.stemWord(k) in d2:  # 如果用户的词的词根存在于词库d2的词根库中
-            d2[k] = d2[stem.stemWord(k)]  # 按照词根进行评级
         else:
-            d2[k] = 3  # 如果k的词根都不在，那么就当认为是3级
+            stem = stemmer.stemWord(k)
+            if stem in d2:  # 如果用户的词的词根存在于词库d2的词根库中
+                d2[k] = d2[stem]  # 按照词根进行评级
+            else:
+                d2[k] = 3  # 如果k的词根都不在，那么就当认为是3级
     return d2
 
 
@@ -115,9 +118,10 @@ def text_difficulty_level(s, d):
     L = freq(s)
 
     lst = []  # a list of tuples, each tuple being (word, difficulty level)
+    stop_words = {'the':1, 'and':1, 'of':1, 'to':1, 'what':1, 'in':1, 'there':1, 'when':1, 'them':1, 'would':1, 'will':1, 'out':1, 'his':1, 'mr':1, 'that':1, 'up':1, 'more':1, 'your':1, 'it':1, 'now':1, 'very':1, 'then':1, 'could':1, 'he':1, 'any':1, 'some':1, 'with':1, 'into':1, 'you':1, 'our':1, 'man':1, 'other':1, 'time':1, 'was':1, 'than':1, 'know':1, 'about':1, 'only':1, 'like':1, 'how':1, 'see':1, 'is':1, 'before':1, 'such':1, 'little':1, 'two':1, 'its':1, 'as':1, 'these':1, 'may':1, 'much':1, 'down':1, 'for':1, 'well':1, 'should':1, 'those':1, 'after':1, 'same':1, 'must':1, 'say':1, 'first':1, 'again':1, 'us':1, 'great':1, 'where':1, 'being':1, 'come':1, 'over':1, 'good':1, 'himself':1, 'am':1, 'never':1, 'on':1, 'old':1, 'here':1, 'way':1, 'at':1, 'go':1, 'upon':1, 'have':1, 'had':1, 'without':1, 'my':1, 'day':1, 'be':1, 'but':1, 'though':1, 'from':1, 'not':1, 'too':1, 'another':1, 'this':1, 'even':1, 'still':1, 'her':1, 'yet':1, 'under':1, 'by':1, 'let':1, 'just':1, 'all':1, 'because':1, 'we':1, 'always':1, 'off':1, 'yes':1, 'so':1, 'while':1, 'why':1, 'which':1, 'me':1, 'are':1, 'or':1, 'no':1, 'if':1, 'an':1, 'also':1, 'thus':1, 'who':1, 'cannot':1, 'she':1, 'whether':1} # ignore these words while computing the artile's difficulty level
     for x in L:
         word = x[0]
-        if word in d:
+        if word not in stop_words and word in d:
             lst.append((word, d[word]))
 
     lst2 = sort_in_descending_order(lst)  # most difficult words on top
diff --git a/app/static/config.yml b/app/static/config.yml
index e6f7ef1..285f31f 100644
--- a/app/static/config.yml
+++ b/app/static/config.yml
@@ -7,6 +7,7 @@ css:
 js:
   head: # 在页面加载之前加载
     - ../static/js/jquery.js
+    - ../static/js/read.js
     - ../static/js/word_operation.js
   bottom: # 在页面加载完之后加载
     - ../static/js/fillword.js
diff --git a/app/static/js/fillword.js b/app/static/js/fillword.js
index ba249dd..b967633 100644
--- a/app/static/js/fillword.js
+++ b/app/static/js/fillword.js
@@ -1,9 +1,5 @@
 let isRead = true;
 let isChoose = true;
-let reader = window.speechSynthesis; // 全局定义朗读者，以便朗读和暂停
-let current_position = 0; // 朗读文本的当前位置
-let original_position = 0; // 朗读文本的初始位置
-let to_speak = ""; // 朗读的初始内容
 
 function getWord() {
     return window.getSelection ? window.getSelection() : document.selection.createRange().text;
@@ -11,7 +7,7 @@ function getWord() {
 
 function fillInWord() {
     let word = getWord();
-    if (isRead) read(word);
+    if (isRead) Reader.read(word, inputSlider.value);
     if (!isChoose) return;
     const element = document.getElementById("selected-words");
     element.value = element.value + " " + word;
@@ -19,50 +15,17 @@ function fillInWord() {
 
 document.getElementById("text-content").addEventListener("click", fillInWord, false);
 
-function makeUtterance(str, rate) {
-    let msg = new SpeechSynthesisUtterance(str);
-    msg.rate = rate;
-    msg.lang = "en-US"; // TODO: add language options menu
-    msg.onboundary = ev => {
-        if (ev.name == "word") {
-            current_position = ev.charIndex;
-        }
-    }
-    return msg;
-}
-
-const sliderValue = document.getElementById("rangeValue"); // 显示值
-const inputSlider = document.getElementById("rangeComponent"); // 滑块元素
+const sliderValue = document.getElementById("rangeValue");
+const inputSlider = document.getElementById("rangeComponent");
 inputSlider.oninput = () => {
-    let value = inputSlider.value; // 获取滑块的值
+    let value = inputSlider.value;
     sliderValue.textContent = value + '×';
-    if (!reader.speaking) return;
-    reader.cancel();
-    let msg = makeUtterance(to_speak.substring(original_position + current_position), value);
-    original_position = original_position + current_position;
-    current_position = 0;
-    reader.speak(msg);
 };
 
-function read(s) {
-    to_speak = s.toString();
-    original_position = 0;
-    current_position = 0;
-    let msg = makeUtterance(to_speak, inputSlider.value);
-    reader.speak(msg);
-}
-
 function onReadClick() {
     isRead = !isRead;
-    if (!isRead) {
-        reader.cancel();
-    }
 }
 
 function onChooseClick() {
     isChoose = !isChoose;
 }
-
-function stopRead() {
-    reader.cancel();
-}
\ No newline at end of file
diff --git a/app/static/js/read.js b/app/static/js/read.js
new file mode 100644
index 0000000..814f627
--- /dev/null
+++ b/app/static/js/read.js
@@ -0,0 +1,35 @@
+var Reader = (function() {
+    let reader = window.speechSynthesis;
+    let current_position = 0;
+    let original_position = 0;
+    let to_speak = "";
+
+    function makeUtterance(str, rate) {
+        let msg = new SpeechSynthesisUtterance(str);
+        msg.rate = rate;
+        msg.lang = "en-US";
+        msg.onboundary = ev => {
+            if (ev.name == "word") {
+                current_position = ev.charIndex;
+            }
+        }
+        return msg;
+    }
+
+    function read(s, rate) {
+        to_speak = s.toString();
+        original_position = 0;
+        current_position = 0;
+        let msg = makeUtterance(to_speak, rate);
+        reader.speak(msg);
+    }
+
+    function stopRead() {
+        reader.cancel();
+    }
+
+    return {
+        read: read,
+        stopRead: stopRead
+    };
+})();
diff --git a/app/static/js/word_operation.js b/app/static/js/word_operation.js
index ea6a6e8..f043cce 100644
--- a/app/static/js/word_operation.js
+++ b/app/static/js/word_operation.js
@@ -62,6 +62,13 @@ function delete_word(theWord) {
     });
 }
 
+function read_word(theWord) {
+    let to_speak = $("#word_" + theWord).text();
+    original_position = 0;
+    current_position = 0;
+    Reader.read(to_speak, inputSlider.value);
+}
+
 /* 
  * interface Word {
  *   word: string,
@@ -95,6 +102,7 @@ function wordTemplate(word) {
         <a class="btn btn-success" onclick="familiar('${word.word}')" role="button">熟悉</a>
         <a class="btn btn-warning" onclick="unfamiliar('${word.word}')" role="button">不熟悉</a>
         <a class="btn btn-danger" onclick="delete_word('${word.word}')" role="button">删除</a>
+        <a class="btn btn-info" onclick="read_word('${word.word}')" role="button">朗读</a>
     </p>`;
 }
 
diff --git a/app/templates/userpage_get.html b/app/templates/userpage_get.html
index e134d94..68997ef 100644
--- a/app/templates/userpage_get.html
+++ b/app/templates/userpage_get.html
@@ -133,6 +133,7 @@
                     <a class="btn btn-success" onclick="familiar('{{ word }}')" role="button">熟悉</a>
                     <a class="btn btn-warning" onclick="unfamiliar('{{ word }}')" role="button">不熟悉</a>
                     <a class="btn btn-danger" onclick="delete_word('{{ word }}')" role="button">删除</a>
+                    <a class="btn btn-info" onclick="read_word('{{ word }}')" role="button">朗读</a>
                 </p>
             {% endfor %}
         </div>
diff --git a/app/wordfreqCMD.py b/app/wordfreqCMD.py
index e56ba0c..dcee74e 100644
--- a/app/wordfreqCMD.py
+++ b/app/wordfreqCMD.py
@@ -39,7 +39,7 @@ def file2str(fname):#文件转字符
 
 
 def remove_punctuation(s): # 这里是s是形参 (parameter)。函数被调用时才给s赋值。
-    special_characters = '\_©~<=>+-/[]*&$%^@.,?!:;#()"“”—‘’{}|' # 把里面的字符都去掉
+    special_characters = '\_©~<=>+/[]*&$%^@.,?!:;#()"“”—‘’{}|' # 把里面的字符都去掉
     for c in special_characters:
         s = s.replace(c, ' ') # 防止出现把 apple,apple 移掉逗号后变成 appleapple 情况
     s = s.replace('--', ' ')