定语从句是比较麻烦哦,但不用纠结,只要从头到尾梳理一下,一步一步来,就比较清晰了.^^*
这个题里面的先行词是The Second World War(n.),主句是The Second World War ended in 1945.
这里可以用最简单的方法,除掉所有主句成分,把选项(when,in which)和先行词(The Second World War)代进剩余部分(millions of people were killed ),看符不符合句意,一般定语从句在选择连接词时也很常用.
A就成了:When The Second World War(n.) millions of people were killed.
C则是:In the Second World War millions of people were killed.
这时候你就会发现,‘when’后面的成了名词,而when是副词,副词修饰动词和形容词,所以就可以排除掉A啦!