diff --git a/README.md b/README.md
index c2fcb37..2691088 100644
--- a/README.md
+++ b/README.md
@@ -73,8 +73,11 @@ $ go get github.com/Tinywan/golang-tutorial
 ######  30 - 错误处理  
 ######  31 - 自定义错误  
 ######  32 -Panic 和 Recover  
-######  33 - 头等函数  
-######34 - 反射  
+####  头等函数  
+######  33 - 头等函数
+#### 反射  
+###### 34 - 反射  
+####  文件操作   
 ######  [35 - 读文件](/docs/golang_tutorial_35.md)  
 
 #### 文档  
diff --git a/demo/string01.go b/demo/string01.go
index 131697f..36433c7 100644
--- a/demo/string01.go
+++ b/demo/string01.go
@@ -2,12 +2,20 @@ package main
 
 import (
 	"fmt"
+	"os"
+	"strings"
 )
 
-var age int
-
 func main() {
-	name := "Tinywan"
-	fmt.Println(name)
-	fmt.Println(name)
-}
\ No newline at end of file
+	os.Setenv("Name", "Tinywan")
+	fmt.Println("Name = ", os.Getenv("Name"))
+	fmt.Println("Bar", os.Getenv("bar"))
+	fmt.Println()
+
+	fmt.Println()
+	for _, e := range os.Environ() {
+		pair := strings.Split(e, "=")
+		fmt.Println(pair[0])
+	}
+}
+go
\ No newline at end of file
diff --git a/docs/golang_tutorial_35.md b/docs/golang_tutorial_35.md
index d5e0167..bbb3573 100644
--- a/docs/golang_tutorial_35.md
+++ b/docs/golang_tutorial_35.md
@@ -1,7 +1,9 @@
 
 35 - 读取文件  
 ========================
-
+<div align="center">
+  <img src="../images/golang-read-files.png"/><br><br>
+</div>  
 上一节：[第十六篇 结构体](/docs/golang_tutorial_16.md)  
 下一节：[第十八篇 接口一](/docs/golang_tutorial_18.md)  
 
diff --git a/images/golang-read-files.png b/images/golang-read-files.png
new file mode 100644
index 0000000..9326bfe
Binary files /dev/null and b/images/golang-read-files.png differ