短文改错。
假定英语课上老师要求同桌交换修改作文， 请你修改你同桌写的以下作文。文中共有十处语
言错误， 每句中最多有两处。错误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，在该词下面写出改正后的词。
注意： 每处错误及修改均仅限一次;只允许修改10处， 多者从第11处起不计分。
One day I had happened to find a chatting room in my QQ, there people were chatting in English. I tried
to chat with any of them. To my surprise, I found the oral English of some junior students were better than
me. I asked them for advice but they told me practise more on QQ. So every day after that I would spend one
hour practise my oral English on QQ. Day by day I learned many useful words and expressions. With time
went by, I found that I could even communicate with some college students free.
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。利用上述给定的装置由铝片与氢氧化钠溶液反应制取氢气，装置的连接顺序为（填小写字母）a接 或a接 ；