质量为3kg的物体,静止在水平地面上.物体与地面间的动摩擦因数为0.5,最大静摩擦力与滑动摩擦力大小视为相等.给物体一水平拉力,则
选择适当的句子补全下面5组对话。
A. It's red. B. Thank you. C. I hear a duck.
D. Good morning, Ben. E. Soup, please.