单选题 It proved that the old woman she had been taking care of was indeed her own mother.
A. turned over B. turned in
C. turned down D. turned out

【正确答案】 D
【答案解析】prove意为“证明”，turn out意为“结果是，证明是”，意思相近。其它选项A意为“打翻”；B意为“上缴”；C意为“把声音变小”。