She could not get rid of the persistent feeling( )if she wer

选C.
关键：that 引导同位语从句,没有实际意义,只起连接句子作用.
方法：if 状语从句后置,变化句子结构——
She could not get rid of the persistent feeling 【that】she would have cause to regret
it bitterly if she were to leave the house.
句子意思：
她无法摆脱这种挥之不去的感觉,即如果她离开这所房子,她就会因此事痛憾.
语法现象：
that 引导同位语从句
if 引导虚拟条件句
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