题目

要除掉粗盐中含有的氯化镁、硫酸镁等杂质。现设计一个除杂质的方案：把盐溶液溶于水，过滤成澄清溶液，再进行下列各步骤的处理：①加入氯化钡溶液至沉淀完全；②用盐酸调节pH至溶液呈微酸性；③加入NaOH溶液至沉淀完全；④过滤废弃滤出的沉淀；⑤加入碳酸钠溶液至沉淀完全；⑥蒸发浓缩使NaCl晶体析出。对上述各处理步骤的顺序安排合理的是（ ） A．①②③④⑤⑥B．③①⑤④②⑥C．②①③④⑤⑥D．②③⑤④①⑥Correction 3（2017·新课标III卷）假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。增加：在缺词处加一个漏字符号(∧)，并在其下面写出该加的词。删除：把多余的词用斜线(＼)划掉。修改：在错的词下划一横线，并在该词下面写出修改后的词。注意：1. 每处错误及其修改均仅限一词；2. 只允许修改10处，多者(从第11处起)不计分。When I look at this picture of myself. I realize of how fast time flies. I had grown not only physically, and also mentally in the past few years. About one month after this photo was took, I entered my second year of high school and become a new member of the school music club. Around me in picture are the things they were very important in my life at that time: car magazines and musical instruments. I enjoyed studying difference kinds of cars and planes, playing pop music, and collecting the late music albums. This picture often brings back to me many happy memories of your high school days.