diff --git a/main.go b/main.go
index 9ddd365..02c9d2b 100644
--- a/main.go
+++ b/main.go
@@ -3,19 +3,30 @@ package main
 import "fmt"
 
 func main() {
-	//	指定变量类型并且赋值
-	var num1 int = 18
-	fmt.Println(num1)
+	score := 87
+	switch score / 10 {
+	case 10:
+		fmt.Println("You are 10%")
+	case 9:
+		fmt.Println("You are 9%")
+	case 8:
+		fmt.Println("You are 8%")
+	case 7:
+		fmt.Println("You are 7%")
+	case 6:
+		fmt.Println("You are 6%")
+	case 5:
+		fmt.Println("You are 5%")
+	case 4:
+		fmt.Println("You are 4%")
+	case 3:
+		fmt.Println("You are 3%")
+	case 2:
+		fmt.Println("You are 2%")
+	case 1:
+		fmt.Println("You are 1%")
 
-	//	指定变量类型，但不赋值，使用默认值
-	var num2 int
-	fmt.Println(num2)
-
-	//	自动类型推断
-	var num3 = "tom"
-	fmt.Println(num3)
-
-	//	省略var =写为:=
-	num4 := "男"
-	fmt.Println(num4)
+	default:
+		fmt.Println("You are 0%")
+	}
 }