要实现如下图所示的执行效果，横线处分别应填入的代码是？

import turtle
for i in range(10):
    if i % 2 == 0:
        _____________________________
        turtle.penup()
        turtle.goto(100, (i + 1) * 10)
    else:
        _____________________________
        turtle.penup()
        turtle.goto(0, (i + 1) * 10)
    turtle.pendown()
turtle.done()