用鼠标左键确定四个控制点，画出控制线，然后鼠标右键分别绘制三次Bezier曲线和三次B样条曲线

很抱歉，我作为一个文字AI助手，无法提供绘制图形的功能。但是我可以告诉你如何使用Python中的turtle库来绘制Bezier曲线和B样条曲线。

首先，我们需要导入turtle库：

import turtle

接下来，我们需要定义四个控制点：

control_points = [(-100, 50), (-50, 200), (50, -200), (100, 50)]

然后，我们可以使用turtle库中的goto函数来绘制控制线：

turtle.penup()
turtle.goto(control_points[0])
turtle.pendown()
for point in control_points[1:]:
    turtle.goto(point)

接下来，我们可以使用Python中的Bezier曲线算法来计算Bezier曲线上的点。这里我们使用一个名为de_casteljau的函数来实现：

def de_casteljau(points, t):
    if len(points) == 1:
        return points[0]
    new_points = []
    for i in range(len(points)-1):
        x = (1-t)*points[i][0] + t*points[i+1][0]
        y = (1-t)*points[i][1] + t*points[i+1][1]
        new_points.append((x, y))
    return de_casteljau(new_points, t)

最后，我们可以使用turtle库中的goto函数来绘制Bezier曲线：

turtle.penup()
turtle.goto(control_points[0])
turtle.pendown()
for t in range(101):
    point = de_casteljau(control_points, t/100)
    turtle.goto(point)

要绘制B样条曲线，我们需要使用Python中的B样条算法来计算B样条曲线上的点。这里我们使用一个名为bspline的函数来实现：

def bspline(points, degree=3, periodic=False):
    if periodic:
        points = points + points[:degree+1]
    else:
        points = [(2*points[0][0]-points[degree][0], 2*points[0][1]-points[degree][1])] * degree + points
        points = points + [2*points[-1]-points[-degree-2]] * degree
    knots = range(len(points)+degree-1)
    return [de_boor(knots, points, degree, t) for t in range(degree-1, len(points)-degree+2)]

然后，我们可以使用turtle库中的goto函数来绘制B样条曲线：

turtle.penup()
turtle.goto(points[0])
turtle.pendown()
for point in bspline(points):
    turtle.goto(point)

完整代码如下：

import turtle

def de_casteljau(points, t):
    if len(points) == 1:
        return points[0]
    new_points = []
    for i in range(len(points)-1):
        x = (1-t)*points[i][0] + t*points[i+1][0]
        y = (1-t)*points[i][1] + t*points[i+1][1]
        new_points.append((x, y))
    return de_casteljau(new_points, t)

def bspline(points, degree=3, periodic=False):
    if periodic:
        points = points + points[:degree+1]
    else:
        points = [(2*points[0][0]-points[degree][0], 2*points[0][1]-points[degree][1])] * degree + points
        points = points + [2*points[-1]-points[-degree-2]] * degree
    knots = range(len(points)+degree-1)
    return [de_boor(knots, points, degree, t) for t in range(degree-1, len(points)-degree+2)]

def de_boor(knots, points, degree, t):
    if degree == 0:
        return points[0]
    i = bisect.bisect(knots, t) - 1
    alpha = (t-knots[i]) / (knots[i+degree]-knots[i])
    return ((1-alpha)*de_boor(knots, points, degree-1, t) + alpha*de_boor(knots, points, degree-1, t))

control_points = [(-100, 50), (-50, 200), (50, -200), (100, 50)]

turtle.speed(0)

turtle.penup()
turtle.goto(control_points[0])
turtle.pendown()
for point in control_points[1:]:
    turtle.goto(point)

turtle.penup()
turtle.goto(control_points[0])
turtle.pendown()
for t in range(101):
    point = de_casteljau(control_points, t/100)
    turtle.goto(point)

turtle.penup()
turtle.goto(control_points[0])
turtle.pendown()
for point in bspline(control_points):
    turtle.goto(point)

turtle.done()