diff --git a/component.go b/component.go
index 677efde..db27699 100644
--- a/component.go
+++ b/component.go
@@ -1,8 +1,6 @@
 package ecs
 
 import (
-	"fmt"
-
 	"github.com/yohamta/donburi"
 )
 
@@ -20,32 +18,6 @@ func (c *ComponentType[T]) Set(entry *Entry, component *T) {
 	c.ComponentType.Set(entry.Entry, component)
 }
 
-// Each iterates over the entities that have the component.
-// 使用Each方法时必须在World线程中执行，即调用World.Execute执行
-func (c *ComponentType[T]) Each(w World, callback func(*Entry)) {
-	c.ComponentType.Each(w.(*world).world, func(entry *donburi.Entry) {
-		callback(&Entry{Entry: entry})
-	})
-}
-
-// First returns the first entity that has the component.
-// 使用First方法时必须在World线程中执行，即调用World.Execute执行
-func (c *ComponentType[T]) First(w World) (*Entry, bool) {
-	entry, ok := c.ComponentType.First(w.(*world).world)
-	return &Entry{entry}, ok
-}
-
-// MustFirst returns the first entity that has the component or panics.
-// 使用MustFirst方法时必须在World线程中执行，即调用World.Execute执行
-func (c *ComponentType[T]) MustFirst(w World) *Entry {
-	e, ok := c.First(w)
-	if !ok {
-		panic(fmt.Sprintf("no entity has the component %s", c.ComponentType.Name()))
-	}
-
-	return e
-}
-
 // SetValue sets the value of the component.
 func (c *ComponentType[T]) SetValue(entry *Entry, value T) {
 	c.ComponentType.SetValue(entry.Entry, value)
diff --git a/examples/rtss/main.go b/examples/rtss/main.go
index 0c20e5e..9fde78d 100644
--- a/examples/rtss/main.go
+++ b/examples/rtss/main.go
@@ -1,10 +1,6 @@
 package main
 
-import (
-	"fmt"
-	"math"
-	"strconv"
-)
+import "fmt"
 
 func main() {
 	// w := ecs.NewWorld(20)
@@ -43,10 +39,14 @@ func main() {
 	// }
 	// time.Sleep(5 * time.Second)
 
-	f := 2.1
-	i := math.Floor(f)
-	d := f - i
-	fmt.Println(f, i, d)
-	f1, _ := strconv.ParseFloat(fmt.Sprintf("%.2f", d), 64)
-	fmt.Println(f1)
+	// f := 2.1
+	// i := math.Floor(f)
+	// d := f - i
+	// fmt.Println(f, i, d)
+	// f1, _ := strconv.ParseFloat(fmt.Sprintf("%.2f", d), 64)
+	// fmt.Println(f1)
+
+	var a []int
+	len := len(a)
+	fmt.Println(len)
 }
diff --git a/world.go b/world.go
index 9442efa..f0bc4ff 100644
--- a/world.go
+++ b/world.go
@@ -45,7 +45,7 @@ type (
 		Resume()
 		SetSpeed(speed float64) error
 		AddSystem(sys ...ISystem)
-		// 在世界线程执行
+		// 在世界中执行逻辑(在世界运行线程中)
 		Execute(fn ExecuteFunc)
 		Close()
 		// 世界时间间隔