“一国两制”的构想是针对下列哪一问题提出来的？（   ）                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

A．澳门问题

B．台湾问题

C．香港问题

D．钓鱼岛问题

车削薄壁零件时，应控制主偏角，使轴向力和径向力朝向工件刚性差的方向减小。