diff --git a/zh/07.6.md b/zh/07.6.md
index e33a97f8..5517cded 100644
--- a/zh/07.6.md
+++ b/zh/07.6.md
@@ -9,15 +9,15 @@
 
 ```Go
 
-		fmt.Println(strings.Contains("seafood", "foo"))
-		fmt.Println(strings.Contains("seafood", "bar"))
-		fmt.Println(strings.Contains("seafood", ""))
-		fmt.Println(strings.Contains("", ""))
-		//Output:
-		//true
-		//false
-		//true
-		//true
+fmt.Println(strings.Contains("seafood", "foo"))
+fmt.Println(strings.Contains("seafood", "bar"))
+fmt.Println(strings.Contains("seafood", ""))
+fmt.Println(strings.Contains("", ""))
+//Output:
+//true
+//false
+//true
+//true
 
 ```
 
@@ -27,9 +27,9 @@
 
 ```Go
 
-		s := []string{"foo", "bar", "baz"}
-		fmt.Println(strings.Join(s, ", "))
-		//Output:foo, bar, baz		
+s := []string{"foo", "bar", "baz"}
+fmt.Println(strings.Join(s, ", "))
+//Output:foo, bar, baz		
 ```
 
 - func Index(s, sep string) int 
@@ -38,10 +38,10 @@
 
 ```Go
 
-		fmt.Println(strings.Index("chicken", "ken"))
-		fmt.Println(strings.Index("chicken", "dmr"))
-		//Output:4
-		//-1
+fmt.Println(strings.Index("chicken", "ken"))
+fmt.Println(strings.Index("chicken", "dmr"))
+//Output:4
+//-1
 ```
 - func Repeat(s string, count int) string
 
@@ -49,8 +49,8 @@
 
 ```Go
 
-		fmt.Println("ba" + strings.Repeat("na", 2))
-		//Output:banana
+fmt.Println("ba" + strings.Repeat("na", 2))
+//Output:banana
 ```
 - func Replace(s, old, new string, n int) string
 
@@ -58,10 +58,10 @@
 
 ```Go
 
-		fmt.Println(strings.Replace("oink oink oink", "k", "ky", 2))
-		fmt.Println(strings.Replace("oink oink oink", "oink", "moo", -1))
-		//Output:oinky oinky oink
-		//moo moo moo
+fmt.Println(strings.Replace("oink oink oink", "k", "ky", 2))
+fmt.Println(strings.Replace("oink oink oink", "oink", "moo", -1))
+//Output:oinky oinky oink
+//moo moo moo
 ```
 - func Split(s, sep string) []string
 
@@ -69,14 +69,14 @@
 
 ```Go
 
-		fmt.Printf("%q\n", strings.Split("a,b,c", ","))
-		fmt.Printf("%q\n", strings.Split("a man a plan a canal panama", "a "))
-		fmt.Printf("%q\n", strings.Split(" xyz ", ""))
-		fmt.Printf("%q\n", strings.Split("", "Bernardo O'Higgins"))
-		//Output:["a" "b" "c"]
-		//["" "man " "plan " "canal panama"]
-		//[" " "x" "y" "z" " "]
-		//[""]
+fmt.Printf("%q\n", strings.Split("a,b,c", ","))
+fmt.Printf("%q\n", strings.Split("a man a plan a canal panama", "a "))
+fmt.Printf("%q\n", strings.Split(" xyz ", ""))
+fmt.Printf("%q\n", strings.Split("", "Bernardo O'Higgins"))
+//Output:["a" "b" "c"]
+//["" "man " "plan " "canal panama"]
+//[" " "x" "y" "z" " "]
+//[""]
 ```
 
 - func Trim(s string, cutset string) string
@@ -85,8 +85,8 @@
 	
 ```Go
 
-		fmt.Printf("[%q]", strings.Trim(" !!! Achtung !!! ", "! "))
-		//Output:["Achtung"]
+fmt.Printf("[%q]", strings.Trim(" !!! Achtung !!! ", "! "))
+//Output:["Achtung"]
 ```
 
 - func Fields(s string) []string
@@ -95,8 +95,8 @@
 	
 ```Go
 
-		fmt.Printf("Fields are: %q", strings.Fields("  foo bar  baz   "))
-		//Output:Fields are: ["foo" "bar" "baz"]
+fmt.Printf("Fields are: %q", strings.Fields("  foo bar  baz   "))
+//Output:Fields are: ["foo" "bar" "baz"]
 ```
 
 ## 字符串转换
@@ -106,41 +106,41 @@
 
 ```Go
 
-		package main
-		
-		import (
-			"fmt"
-			"strconv"
-		)
-		
-		func main() {
-			str := make([]byte, 0, 100)
-			str = strconv.AppendInt(str, 4567, 10)
-			str = strconv.AppendBool(str, false)
-			str = strconv.AppendQuote(str, "abcdefg")
-			str = strconv.AppendQuoteRune(str, '单')
-			fmt.Println(string(str))
-		}
+package main
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func main() {
+	str := make([]byte, 0, 100)
+	str = strconv.AppendInt(str, 4567, 10)
+	str = strconv.AppendBool(str, false)
+	str = strconv.AppendQuote(str, "abcdefg")
+	str = strconv.AppendQuoteRune(str, '单')
+	fmt.Println(string(str))
+}
 ```
 
 - Format 系列函数把其他类型的转换为字符串
 ```Go
 
-		package main
-	
-		import (
-			"fmt"
-			"strconv"
-		)
-		
-		func main() {
-			a := strconv.FormatBool(false)
-			b := strconv.FormatFloat(123.23, 'g', 12, 64)
-			c := strconv.FormatInt(1234, 10)
-			d := strconv.FormatUint(12345, 10)
-			e := strconv.Itoa(1023)
-			fmt.Println(a, b, c, d, e)
-		}
+package main
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func main() {
+	a := strconv.FormatBool(false)
+	b := strconv.FormatFloat(123.23, 'g', 12, 64)
+	c := strconv.FormatInt(1234, 10)
+	d := strconv.FormatUint(12345, 10)
+	e := strconv.Itoa(1023)
+	fmt.Println(a, b, c, d, e)
+}
 
 ```
 
@@ -148,30 +148,30 @@
 
 ```Go
 
-		package main
+package main
 
-		import (
-			"fmt"
-			"strconv"
-		)
-		func checkError(e error){
-			if e != nil{
-				fmt.Println(e)
-			}
-		}
-		func main() {
-			a, err := strconv.ParseBool("false")
-			checkError(err)
-			b, err := strconv.ParseFloat("123.23", 64)
-			checkError(err)
-			c, err := strconv.ParseInt("1234", 10, 64)
-			checkError(err)
-			d, err := strconv.ParseUint("12345", 10, 64)
-			checkError(err)
-			e, err := strconv.Atoi("1023")
-			checkError(err)
-			fmt.Println(a, b, c, d, e)
-		}
+import (
+	"fmt"
+	"strconv"
+)
+func checkError(e error){
+	if e != nil{
+		fmt.Println(e)
+	}
+}
+func main() {
+	a, err := strconv.ParseBool("false")
+	checkError(err)
+	b, err := strconv.ParseFloat("123.23", 64)
+	checkError(err)
+	c, err := strconv.ParseInt("1234", 10, 64)
+	checkError(err)
+	d, err := strconv.ParseUint("12345", 10, 64)
+	checkError(err)
+	e, err := strconv.Atoi("1023")
+	checkError(err)
+	fmt.Println(a, b, c, d, e)
+}
 
 ```