第17 步：我们现在将 newrise 添加到 bally 以获得足球的新 y 坐标。
现在我们的球有了一个新的 y 坐标。我们将使用 netx 作为我们的 x 坐标，因为我们希望球向网移动，但end_y作为 y 坐标，这样球只有在用户正确的情况下才会击中网！
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stage.set_axis(100)
stage.create_grid_overlay(10, "grey")
stage.set_background("soccerfield")
ballx = -80
bally = random.randint(-100,100)
# sprite = codesters.Sprite("image", x, y)
ball = codesters.Sprite("soccerball", ballx, bally)
netx = 90
nety = random.randint(-100,100)
# sprite = codesters.Sprite("image", x, y)
net = codesters.Sprite("soccernet", netx, nety)
net.flip_right_left()
#sprite = codesters.Line(x-start, y-start, x-end, y-end, "color")
line = codesters.Line(ballx, bally, netx, nety, "blue")
slopeguess = float(line.ask("What is the slope of this line?"))
rise = nety - bally
run = netx - ballx
slope = rise / run
# sprite = codesters.Text("text", x, y)
sprite = codesters.Text(slope, 0, 30)
newrise = slopeguess*run
