一定温度下的难溶电解质AmBn在水溶液中达到溶解平衡时。已知下表数据
| 物质 |
Fe(OH)2 |
Cu(OH)2 |
Fe(OH)3 |
| Ksp/25℃ |
8.0×10-16 |
2.2×10-20 |
4.0×10-38 |
| 完全沉淀时的PH值范围 |
≥9.6 |
≥6.4 |
3～4 |
对含等物质的量CuSO4、FeSO4、Fe2(SO4)3的混合溶液的说法，不科学的是
A．向该混合溶液中逐滴加入NaOH溶液，最先看到红褐色沉淀B．该溶液中c(SO42-)：｛c(Cu2+)+c(Fe2+)+c(Fe3+)｝＞5:4C．向该溶液中加入适量氯水，并调节pH值到3～4后过滤，得到纯净的CuSO4溶液D．向该溶液中加少量铁粉即能观察到红色固体析出
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I’m sure that your letter will get______ attention. They know you’re waiting for the reply. 
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