下列实验操作不能达到目的是（ ）
选项 |
目的 |
操作 |
A |
清洗暖水瓶中的水垢 |
先用醋酸浸泡，再用水冲洗 |
B |
清洗碘升华实验所用试管 |
先用酒精清洗，再用水清洗 |
C |
区分腈纶线、羊毛线 |
点燃，闻燃烧产生的气味 |
D |
测定碳酸钠溶液的pH |
用玻璃棒蘸取溶液，滴在湿润的pH试纸上 |
A．AB．BC．CD．D
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