单选题
The thief might have left the money untouched for the simple reason______he didn't know it was there.
【正确答案】
C
【答案解析】[精析] 本题考查的是同位语。句中的the simple reason与he didn't know it was there是同位的关系，引导同位语的关联词多为that，且that在句中不做任何成分。这里关联词后面是完整的句子，不缺任何成分，因此A，B，D都不合适，故C正确。