当事人以车辆进行抵押，抵押合同自( )之日起生效。
A．签订
B．到主管部门登记
C．当事人不履行债务
D．主合同生效
参考答案：B
王爷爷家去年收玉米64780千克，今年比去年多收了4947千克，王爷爷家今年收玉米多少千克？约多少万千克？
It's your choice! ____ she leaves ____ I will! [ ]
A. Neither; nor
B. Either; or
C. Both; and
D. Not only; but also
