题目

When the clerk at the counter was rude to her, she rings Tony up and told the clerk to speak to him.       答案：把rings 改成rang相同条件下，1体积X2（气）和3体积Y2（气）生成2体积Z（气），则Z的化学式为( )A．XY3 B．XY C．X2Y D．X3Y2