The war and the suffering ___caused had great efforts on him.
问题描述：
The war and the suffering ___caused had great efforts on him.
A.that B.which C.what D.it
答
应该选D,这个句子的结构是这样的：
The war and the suffering {(that) it caused}定语从句 had great efforts on him.
战争以及战争带来的苦难给他造成了巨大的影响.