问题
填空题
[A] stamp
[B] zoo
[C] blackboard
[D] train
[E] post office
[F] park
[G] bank
People put it on an envelope.
答案
参考答案：A
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[A] stamp
[B] zoo
[C] blackboard
[D] train
[E] post office
[F] park
[G] bank
People put it on an envelope.
参考答案：A
下表各组物质分类不正确的是（ ）
| A | B | C | D | |
| 液氧、空气、Cl2、铜丝 | HCl、H2SO4、H2O、HNO3 | NaCl溶液、盐酸、CuSO4•5H2O | NH3、NaOH、BaSO4固体 | |
| 分类标准 | 单质 | 酸 | 混合物 | 电解质 |
| 不属于该类的物质 | 空气 | H2O | 盐酸 | NH3 |
A．A
B．B
C．C
D．D