Hewasveryrudetothecustomsofficer,

来源：语文精选馆 2.62W

He was very rude to the customs officer, ________ of course made things even worse.

C．which D．who

C　句意：他对海关官员非常粗鲁，这使得事情更加糟糕。分析句子结构可知“________ of course made things even worse”为定语从句，从句中缺少主语且指代前面整个句子的内容，所以用which，故选D。