某溶液中滴入KSCN溶液后变红，说明溶液中存在 A．NO3

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问题选择题

某溶液中滴入KSCN溶液后变红，说明溶液中存在

A．NO₃^－

B．Fe³^＋

C．SO₄²^－

D．Mg²^＋

答案

答案：B

Fe³^＋＋3SCN^―="Fe" (SCN)₃ ,血红色，选B。

多项选择题

管井与孔壁之间不宜填充的滤料有()。

A.粉细砂

B.中粗砂

C.棱角形石渣料

D.风化料

E.黏质岩石成分的砾石

句型转换

句型转换。

1. When he was 8,he began to learn to skate. (改为同义句)

_________ _________eight , he to learn to skate.

2. It takes about15 minutes to walk home. (就画线部分提问)

_______ ________It to walk home?

3. I think Jim will come back. (改为反意疑问句)

I think Jim will come back, _________?

4. I'm planning to visit my teacher this Sunday. (就画线部分提问)

_______ _________ _______Planning this Sunday?

5. "Are you going to visit Zigong next week?"Father asked me.(改为间接引语)

Father me ________going to visit Zigong the next week