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问题 选择题

下列离子方程式的书写正确的是（　　）

A．氢氧化钡溶液与等物质的量的稀硫酸混合：Ba2++2OH-+2H++SO42-═BaSO4↓+2H2O

B．玻璃试剂瓶被烧碱溶液腐蚀：SiO2+2Na++2OH-=Na2SiO3↓+H2O

C．高锰酸钾酸性溶液吸收二氧化硫：SO2+MnO4-+4H+=SO42-+Mn2++2H2O

D．从酸化的海带灰浸出液中提取碘：2I-+H2O2=I2+2OH-

答案

A、拆分及配比均符合，故A正确；

B、Na2SiO3是易溶于水易电离的物质，应写成离子形式，故B错误；

C、得失电子不守恒，故C错误；

D、酸性条件下不可能存在OH-，故D错误；

故选：A．

操作题

请画图解释插入水中的筷子弯折的原因。
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填空题

用所给词的正确形式填空。

1. How ________ (care) Jim was! He made few mistakes in the math competition.

2. —Who is your ________ (close) person in your family?  

    —My grandmother is.

3. He got a ________ (bad) result in English this term than last term, he didn’t try his best.

4. Tommy is very ________ (happy) because he lost his bike.

5. —Whose shoes are these?

    —They are the ________. (run)

6. The Greens will have a ________ (令人愉快的) trip because they plan everything carefully.

7. He does well in his geography, so he can answer the teacher's questions ________ (正确).

8. The ________(高度) of Millie is 135cm, I’m really sorry for it.

9. We can learn a lot from ________. They will take part in the important meeting tonight. (英雄)

10.The Great Wall is one of ________(著名) places of interest in Beijing.
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