China's new food law provides for a food recall system________ producers have to stop production if their food isn't up to standards.[ ]

A．where  

B．that

C．when  

D．which

微机控制燃料供给系统包括（）供给系统、（）供给系统，（）控制系统和其他为电子控制装置提供发动机信号的（）等四个部分。