搜题请搜索小程序“爱下问搜题”
问题 选择题

下列离子方程式正确的是

A．FeCl2溶液中通入Cl2：Fe2+ + Cl2==Fe3+ + 2Cl－

B．硅酸和烧碱溶液中和：H2SiO3 + 2OH-==SiO32- + 2H2O

C．向硫酸铝钾溶液中加入少量的氢氧化钡溶液：

2Ba2+ + 4OH- + 2SO42 -+ Al3+ ==2BaSO4↓+ 2H2O + AlO-2

D．向硅酸钠溶液中通入过量的CO2：SiO32- + CO2 + H2O ="=" H2SiO3↓+ CO32-

答案

答案：B

句型转换

按要求改写句型。

1. He's going to tell me all about it. (改为一般疑问句)

    ________ he _________ tell me all about it?

2. They are going to the West Lake. (改为否定句)

    They ________ to the West Lake.

3. She's going to work hard at English this term.(就划线部分提问)

    _________ she ________ this term?

4. They are going to leave next Tuesday.(就划线部分提问)

    ________ they going to leave?

5. The children are going to the zoo by bike. (就划线部分提问)

     ________ the children ________ to the zoo?
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单项选择题

公共政策系统的“神经”系统是（）

A．信息子系统

B．执行子系统

C．反馈子系统

D．决策子系统
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