题目

Joining the firm as a clerk, he got rapid promotion through his diligence and _____ as a manager last year. A. dropped out              B. came back  C. ended up           D. started off 答案：C 解析: 略下图为硝酸钾的溶解度曲线。 (1)硝酸钾的溶解度随温度升高而___________ 。 (2)20℃时，向100 g水中加入55 g硝酸钾，充分溶解后得到的溶液_____________ （填“是”或“不是”）饱和溶液，其原因是________；再将温度升高到40℃，该溶液中溶质的质量分数__________（填“不变”“变大”或“变小”）。