题目

Have you ever had the strange feeling that you were being watched? You turned around and ,sure enough, someone was looking right at you! Parapsychologists（灵学家）say that humans have a natural ability to sense when someone is looking at them. To research whether such a “sixth sense”really exists, Robert Baker, a psychologist（心理学家）at the University of Kentucky, performed two experiments. In the first one, Baker sat behind unknowing people in public places and stared at the backs of their heads for 5 to 15 minutes. The subjects（受试者）were eating, drinking, readings化学反应经常伴随着颜色变化，下列关于颜色的叙述正确的是(　　)①鸡蛋白溶液遇浓硝酸——黄色　②淀粉碘化钾溶液遇碘离子——蓝色　③溴化银见光分解——白色　④热的氧化铜遇乙醇——红色　⑤新制氯水久置后——无色　⑥过氧化钠在空气中久置——淡黄色A．①②③⑤          B．①④⑤           C．②③④⑥              D．④⑤⑥