题目

Breathe, wave and smile. Along with more than 300 other seniors, I marched into the stadium on the afternoon of May 10. The audience burst into deafening cheers. The huge stadium shook with all the whistling and clapping. It was as if a Hollywood superstar had walked on stage. And indeed, every single senior that day was a star of the moment. Each deserved it. The seniors had been preparing for four years for this once-in-a-lifetime moment—the commencement. Seated, I waited anxiously for the opening address. As a foreign exchange student, I was not able to receive a diploma. However,物质的鉴别有多种方法．下列能达到鉴别目的是（　　）①用水鉴别苯、乙醇、溴苯     ②用相互滴加的方法鉴别氨水和AgNO3溶液③点燃鉴别甲烷和乙炔．A．①②B．①③C．②③D．①②③