某实验小组应用如图甲所示装置“探究加速度与物体受力的关系”，已知小车的质量为M，砝码和砝码盘的总质量为m，所使用的打点计时器所 接的交流电的频率为50Hz，实验步骤如下：

A．按图甲所示，安装好实验装置，其中与定滑轮及弹簧测力计相连的细线竖直；

B．调节长木板的倾角，轻推小车后，使小车能沿长木板向下匀速运动；

C．挂上砝码盘，接通电源后，再放开小车，打出一条纸带，由纸带求出小车的加速度；

D．改变砝码盘中砝码的质量，重复步骤C，求得小车在不同合力作用下的加速度．

根据以上实验过程，回答以下问题：

Draw it ____ ____ ____．

    Jack is six years old. He has no sisters. But he has a brother. His brother's name is Mike. Jack likes eating apples, oranges and bananas. Sometimes he eats some of his brother's apples. And his brother often beats（打）him for this. He doesn't like Mike. This September he goes to school. It's the ninth（第九） day at school. Jack and his classmates are having a new lesson.

    "Jack, what is five minus（减） three, please？" asks the teacher.

    "It's…it's…"

    "Now, listen to me," says the teacher, "If your sister has five apples, and you eat three of them…"

    "But I have no sisters." Jack says.

    "Oh, sorry. But do you have any brothers？"

    "Yes."

    "Now, if your brother has five apples, and you eat three of them, tell me now…？"

    "He'll certainly beat me," Jack says quickly.