题目

​​ 随着人口和经济的快速增长，水污染日益加剧，因此污水净化具有重要的意义。如图所示为小明设计的太阳能净水器，在污水净化过程中发生的物态变化是（ ） A . 先熔化，后凝固 B . 先汽化，后液化 C . 先升华，后凝华 D . 先汽化，后凝固 答案：B(2013·宁夏银川一中高三第四次考试)Each of the 400 people received from their boss ________ gift—“Who moved my cheese？”， ________ best­seller in the US, which helped them understand how to deal with changes in their lives and work.A．the; /B．a; /C．a; aD．the; a