使用海龜繪圖，輸出4個300*300的矩形

import turtle
turtle.showturtle() #顯示箭頭，並繪制第一個300*300的矩形
turtle.goto(300,0)
turtle.goto(300,300)
turtle.goto(0,300)
turtle.goto(0,0)

turtle.penup() #繪制第二個300*300的矩形
turtle.goto(400,0)
turtle.pendown()
turtle.goto(700,0)
turtle.goto(700,300)
turtle.goto(400,300)
turtle.goto(400,0)

turtle.penup() #繪制第三個300*300的矩形
turtle.goto(0,-400)
turtle.pendown()
turtle.goto(300,-400)
turtle.goto(300,-100)
turtle.goto(0,-100)
turtle.goto(0,-400)

turtle.penup() #繪制第四個300*300的矩形
turtle.goto(400,-400)
turtle.pendown()
turtle.goto(700,-400)
turtle.goto(700,-100)
turtle.goto(400,-100)
turtle.goto(400,-400)