sc蓝皮section11-9 - ChaseDream

In the face of widespread concern about environmental waste, compact disc manufacturers are attempting to find a replacement for the disposable plastic box in which they package their product.
(A) the disposable plastic box in which they
(B) the disposable plastic box where they
(C) a disposable plastic box in which to
(D) disposable plastic boxes inside which they
(E) the disposable plastic boxes in which to

我一直在AB之间徘徊最后还是选了一个错误的B 答案是A
一直以来都不知道in which和where或者in which和when有什么区别貌似那时候中学时候老师是说可以互换的呀
还请大家帮我解答一下`` 谢谢!!