①用稀盐酸洗涤盛放过石灰水的试剂瓶

②配制浓硫酸和浓硝酸的混合酸时，将浓硝酸沿器壁慢慢加入到浓硫酸中，并不断搅拌；

③用pH试纸测得氯水的pH为2；

④用稀硝酸清洗做过银镜反应实验的试管；

⑤浓硝酸保存在棕色细口瓶中；

⑥将镁条和铝片用导线连接再插进稀NaOH溶液，镁条上产生气泡

⑦某溶液加入NaOH并加热能产生使湿润红色石蕊试纸变蓝的气体，则原溶液中含NH₄⁺．

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。

    I hardly remember my grandmother. She used to holding me on her knees and sing old songs. I was only four when she passes away. She is just a distant memory for me now.

    I remember my grandfather very much. He was tall, with broad shoulder and a beard that turned from black toward gray over the years. He had a deep voice, which set himself apart from others in our small town, he was strong and powerful. In a fact, he even scared my classmates away during they came over to play or do homework with me. However, he was the gentlest man I have never known.

氮化铝（AlN）是一种新型无机材料，广泛应用于集成电路生产领域。某氮化铝中含有碳或氧化铝杂质，现用下图中的一些装置来进行检验，使氮化铝样品和NaOH溶液反应AlN+NaOH+H₂O=NaAlO₂+NH₃↑，根据反应中所生成氨气的体积来测定样品中的氮化铝的

质量分数（实验中导管体积忽略不计）。