diff --git a/scripts/level_data.gd b/scripts/level_data.gd
index 5d46398..f9f41df 100644
--- a/scripts/level_data.gd
+++ b/scripts/level_data.gd
@@ -1,168 +1,188 @@
+## 章节和关卡数据。
 class_name LevelData
 
+
+ 
+## 各章节的名称。
+## [br][br] 
+## [code]CHAP_NAMES[chapter_id]["name-en"][/code] 返回第 [param chapter_id] 章节的英文名称（包含 [code]Ch.[/code] 前缀）。
 const CHAP_NAMES := [
-    {
-        "name-en": "Ch. 1  =P",
-    },
-    {
-        "name-en": "Ch. 2  Add and Multiply",
-    },
-    {
-        "name-en": "Ch. 3  ()",
-    },
-    {
-        "name-en": "Ch. 4  Equal?",
-    },
-    {
-        "name-en": "Ch. 5  <>",
-    }
+	{
+		"name-en": "Ch. 1  =P",
+	},
+	{
+		"name-en": "Ch. 2  Add and Multiply",
+	},
+	{
+		"name-en": "Ch. 3  ()",
+	},
+	{
+		"name-en": "Ch. 4  Equal?",
+	},
+	{
+		"name-en": "Ch. 5  <>",
+	}
 ]
 
+
+## 各关卡的关卡数据。
+## [br][br]
+## [code]LEVEL_DATA[chapter_id][level_id] : Dictionary[/code] 返回第 [param chapter_id] 章节的第 [param level_id] 关卡的关卡数据，以下记为 [code]data[/code]。其中：
+## [br][br]
+## [code]data["name-en"][/code] 为关卡英文名。
+## [br][br]
+## [code]data["question"][/code] 为关卡表达式，用 [code][][/code] 表示无要求的空槽，用 [code]{}[/code] 表示要求为笑脸的空槽。
+## [br][br]
+## [code]data["choices"][/code] 为关卡选项。
 const LEVEL_DATA := [
-    [
-        {
-            "name-en": "=P",
-            "question": "P [] []",
-            "choices": "= P"
-        },
+	[
+		{
+			"name-en": "=P",
+			"question": "P [] []",
+			"choices": "= P"
+		},
   		{
-            "name-en": "Smile",
-            "question": "P {} {}",
-            "choices": "= P P"
-        },
-        {
-            "name-en": "Another Smile",
-            "question": "[] = {}",
-            "choices": "R R P D D"
-        },
+			"name-en": "Smile",
+			"question": "P {} {}",
+			"choices": "= P P"
+		},
+		{
+			"name-en": "Another Smile",
+			"question": "[] = {}",
+			"choices": "R R P D D"
+		},
   		{
-            "name-en": "Reverse",
-            "question": "{} [] []",
-            "choices": "D D = d d"
-        },
+			"name-en": "Reverse",
+			"question": "{} [] []",
+			"choices": "D D = d d"
+		},
   		{
 			"name-en": "Reverse Again",
 			"question": "[] {} {}",
 			"choices": "d d = R R b b"
 		},
   		{
-            "name-en": "Snake",
-            "question": "[] = {} = {} = [] = {} = {}",
-            "choices": "dddddd QQQQQQ RRRRRR DDDDDD PPPPPP qqqqqq"
-        }
-    ],
-    
-    [
-        {
-            "name-en": "0+0=0, 0+1=1",
-            "question": "[] [] {} {} d",
-            "choices": "= + 0 d"
-        },
-        {
-            "name-en": "1+1=1",
-            "question": "[] [] {} {} 1",
-            "choices": "= + d 1"
-        },
-        {
-            "name-en": "Swap",
-            "question": "Q + [] = {} + []",
-            "choices": "P P P P Q Q Q Q"
-        },
-        {
-            "name-en": "Always True",
-            "question": "1 [] {} = {} [] []",
-            "choices": "1++PPdd"
-        },
-        {
-            "name-en": "Make Me Laugh",
-            "question": "1 {} {} = []",
-            "choices": "XDD"
-        },
-        {
-            "name-en": "Reset",
-            "question": "0 [] [] {} []",
-            "choices": "XD=0"
-        },
-        {
-            "name-en": "Not Necessary",
-            "question": "[] {} {} {} {} []",
-            "choices": "QQQQQQ DDXX="
-        },
-        {
-            "name-en": "[EX] Not Really Challenging",
-            "question": "1 [] [] [] {} [] [] [] {} [] {} [] []",
-            "choices": "== ++++++ 11 P q b R"
-        },
-        {
-            "name-en": "[EX] Golden Experience",
-            "question": "{} {} {} {} {} {} {} {} {} {}",
-            "choices": "PP DD qq dd question XXX ="
-        }
-    ],
+			"name-en": "Snake",
+			"question": "[] = {} = {} = [] = {} = {}",
+			"choices": "dddddd QQQQQQ RRRRRR DDDDDD PPPPPP qqqqqq"
+		}
+	],
+	
+	[
+		{
+			"name-en": "0+0=0, 0+1=1",
+			"question": "[] [] {} {} d",
+			"choices": "= + 0 d"
+		},
+		{
+			"name-en": "1+1=1",
+			"question": "[] [] {} {} 1",
+			"choices": "= + d 1"
+		},
+		{
+			"name-en": "Swap",
+			"question": "Q + [] = {} + []",
+			"choices": "P P P P Q Q Q Q"
+		},
+		{
+			"name-en": "Always True",
+			"question": "1 [] {} = {} [] []",
+			"choices": "1++PPdd"
+		},
+		{
+			"name-en": "Make Me Laugh",
+			"question": "1 {} {} = []",
+			"choices": "XDD"
+		},
+		{
+			"name-en": "Reset",
+			"question": "0 [] [] {} []",
+			"choices": "XD=0"
+		},
+		{
+			"name-en": "Not Necessary",
+			"question": "[] {} {} {} {} []",
+			"choices": "QQQQQQ DDXX="
+		},
+		{
+			"name-en": "[EX] Not Really Challenging",
+			"question": "1 [] [] [] {} [] [] [] {} [] {} [] []",
+			"choices": "== ++++++ 11 P q b R"
+		},
+		{
+			"name-en": "[EX] Golden Experience",
+			"question": "{} {} {} {} {} {} {} {} {} {}",
+			"choices": "PP DD qq dd question XXX ="
+		}
+	],
 
-    [
-        {
-            "name-en": "He Goes First",
-            "question": "[] [] + [] = ( [] {} {} ) [] []",
-            "choices": "PP QQ RR X +"
-        },
-        {
-            "name-en": "Still, He Goes First",
-            "question": "[] + [] [] = [] [] ( [] {} {} )",
-            "choices": "PP QQ RR X +"
-        },
-        {
-            "name-en": "It's My Turn",
-            "question": "P ([] [] []) = {} [] [] [] []",
-            "choices": "PP QQ RR ++"
-        },
-        {
-            "name-en": "[EX] Really Challenging",
-            "question": "[] [] [] [] [] {} {} [] [] [] [] {} {} + [] []",
-            "choices": "PPP QQ DD (()) ++ = X"
-        }
-    ],
+	[
+		{
+			"name-en": "He Goes First",
+			"question": "[] [] + [] = ( [] {} {} ) [] []",
+			"choices": "PP QQ RR X +"
+		},
+		{
+			"name-en": "Still, He Goes First",
+			"question": "[] + [] [] = [] [] ( [] {} {} )",
+			"choices": "PP QQ RR X +"
+		},
+		{
+			"name-en": "It's My Turn",
+			"question": "P ([] [] []) = {} [] [] [] []",
+			"choices": "PP QQ RR ++"
+		},
+		{
+			"name-en": "[EX] Really Challenging",
+			"question": "[] [] [] [] [] {} {} [] [] [] [] {} {} + [] []",
+			"choices": "PPP QQ DD (()) ++ = X"
+		}
+	],
 
-    [
-        {
-            "name-en": "Why?",
-            "question": "[] [] {} = {} [] {} = []",
-            "choices": "PP qq ++ 1"
-        },
-        {
-            "name-en": "Where is the Equation?",
-            "question": "[] [] {} {} [] + [] [] {} {} []",
-            "choices": "(())==01PP"
-        },
+	[
+		{
+			"name-en": "Why?",
+			"question": "[] [] {} = {} [] {} = []",
+			"choices": "PP qq ++ 1"
+		},
+		{
+			"name-en": "Where is the Equation?",
+			"question": "[] [] {} {} [] + [] [] {} {} []",
+			"choices": "(())==01PP"
+		},
 
-        {
-            "name-en": "Untitled",
-            "question": "[] [] {} {} [] [] [] []",
-            "choices": "=PPQQ+()"
-        }
-    ],
+		{
+			"name-en": "Untitled",
+			"question": "[] [] {} {} [] [] [] []",
+			"choices": "=PPQQ+()"
+		}
+	],
 
-    [
-        {
-            "name-en": "<",
-            "question": "0 {} {} [] 1",
-            "choices": "XD<"
-        },
-        {
-            "name-en": "<=",
-            "question": "[] X [] {} {} [] + []",
-            "choices": "QQPP<="
-        },
-        {
-            "name-en": "<>",
-            "question": "0 {} P [] [] []",
-            "choices": "<>=P"
-        }
-    ]
+	[
+		{
+			"name-en": "<",
+			"question": "0 {} {} [] 1",
+			"choices": "XD<"
+		},
+		{
+			"name-en": "<=",
+			"question": "[] X [] {} {} [] + []",
+			"choices": "QQPP<="
+		},
+		{
+			"name-en": "<>",
+			"question": "0 {} P [] [] []",
+			"choices": "<>=P"
+		}
+	]
 ]
 
+
+## 获取第 [param chapter_id] 章节的关卡数量。
 static func get_chapter_level_count(chapter_id: int) -> int:
-    return len(LEVEL_DATA[chapter_id])
+	return len(LEVEL_DATA[chapter_id])
+
 
+## 获取章节数量。
 static func get_chapter_count() -> int:
-    return len(LEVEL_DATA)
\ No newline at end of file
+	return len(LEVEL_DATA)