Question

The American people will never forget the 9.11 event and the psychological trauma __________ caused to hundreds of thousands of common households.

A．that

B．it

C．which

D．what

Answer 1

B

解析试题分析：句意：美国人永远不会忘记9.11事件和它给成百上千的家庭带来的心灵创伤。it指代9.11事件，在定语从句中做主语；which和that都做定语从句的关系词，代替先行词做主语，the psychological trauma是先行词，在从句中做宾语，可以省略。what不是定语从句的关系词。 故选B。 
考点: 考查代词的用法。