选哪个,请给出原因.A.where B.that C.when D.which
问题描述：
选哪个,请给出原因.A.where B.that C.when D.which
China's new food law provides for a food recall system______producers have to stop production if their food isn't up to standards.
答
where：引导定语从句,相当于in the system.
这里的system与case/situation一样,相当于一个抽象地点,以为“在这种制度里”,所以用where来引导.