问题 单项选择题

如右图所示,当车厢向前加速运动时,物体M静止于竖直车厢上,当车厢加速度增大时 ()。

A.静摩擦力增加

B.车厢竖直壁对物体的弹力增加

C.物体M掉落

D.物体的加速度不变

答案

参考答案:B

材料分析题

(1)你知道我国现行基本经济制度是什么?并指出坚持这一制度的依据。

                                                                                                                                                              

                                                                                                                                                              

(2)现阶段我国的是如何对待非公有制经济发展的?

                                                                                                                                                              

                                                                                                                                                              

(3)上图反映的内容是否全面?若有不足,请你完善它。(注:请用文字说明)

                                                                                                                                                              

单项选择题 案例分析题