单选题
In some California housing estates, a key alone is insufficient to get someone in the door; his or her voiceprint must also be ______.
【正确答案】
D
【答案解析】[解析] A项，“duplicate”意为“复制”；B项，“perceive”意为“感知，感受”；C项，“acquire”意为“取得，获得”；D项，“verify”意为“证明、证实，核实、查清”，本句是说需要验证他们的声音，因此选择D。