Russia has been observing a day of mourning after amilitary plane crashed on Sunday in which all 92 people on board were killed.上句中的in which可否 直接 改成where,为什么要用in which in和后面的哪个词能构成介词短语吗,请高手帮助下,谢谢
可是句中的on board不就是在飞机里的意思吗