我们已经知道，铁在潮湿的空气里容易生锈．试设计一组实验（也可用图示）证明铁的生锈

阅读理解。

     A few weeks ago, we decided to paint(油漆)the outside of  our house．To save money, we decided to do it

ourselves. On Saturday morning,    we went to the shops and bought some paint and a number of brushes.   We

already had a ladder  (梯子),so we were then ready to start. We began that afternoon with the back of the house.

The next Saturday I went to a football match while my wife painted the front of the house. On Sunday we found

that we could not open any of the front windows.     We got them all open in the end but I  broke three and they

were very expensive to repair. Next time when we try to save money, I shall certainly pay someone to do the work.

1．Why did the writer and his wife decide to paint the house themselves? Because ________.

A．no one else could do the work

B．they didn't want to spend much money

C．they only need to buy some paint

D．windows were expensive to repair

2．Why will they pay someone to work for them next time?

Because they ________.

A．don't want to do the work themselves any more

B．have no paint and brushes

C．want to go to the football match together

D．want to save money

3．"So we were then ready to start" means we ________.

A．had already started the work

B．had everything we need to begin the job

C．were always ready to do the work

D．were happy to start the work

4．On Sunday they could not open ________ of the front windows.

A．both                    

B．some

C．any                      

D．neither

5．The writer broke ________ in the end.

A．three doors                

B．three glasses

C．two windows              

D．three windows

废锅干锅原因是什么？应如何处理？

（8分）化学小组同学在课外读物中看到：“通常CO₂可作灭火剂，但有些物质（如Na）着火，不能用CO₂熄灭。”他们决定探究CO₂与Na反应的产物。

【提出猜想】CO₂与Na反应可能生成4种物质：C、CO、Na₂O和Na₂CO₃。

【查阅资料】

① Na是非常活泼的金属，常温下与O₂、H₂O等物质反应。

②向氯化钯（PdCl₂）溶液中通入CO，产生黑色沉淀。

③Na₂CO₃是白色固体，易溶于水，能与CaCl₂溶液发生反应，化学方程式为：Na₂CO₃+CaCl₂=    CaCO₃↓+2NaCl

④Na₂O是白色固体，与H₂O反应生成NaOH。

⑤CaCl₂、NaCl、Na₂CO₃、NaOH四种溶液分别与无色酚酞溶液作用比较：

分别向右侧溶液中 加入无色酚酞溶液	CaCl2	NaCl	Na2CO3	NaOH
主要实验现象	无色	无色	由无色变为红色	由无色变为红色

【实验过程】同学们在老师的指导下设计了如下图所示装置(部分夹持仪器已略去)。

（1）实验记录

序号	实验操作	主要实验现象	实验结论及解释
①	打开a，关闭b，由长颈漏斗注入稀盐酸	A中产生大量气泡 E中出现浑浊	E中反应的化学方程式为
②	当E中出现浑浊时，打开b，关闭a，点燃酒精灯	D中Na剧烈燃烧，产生白烟 内壁附着黑色、白色固体 G中产生黑色沉淀	反应产物一定 有    和
③	取D中白色固体于试管中，加水溶解，再加入CaCl2溶液	产生白色沉淀	反应产物还有

（2）实验反思

① 实验记录②中，E中出现浑浊再点燃酒精灯的目的是       。

② 装置B、C的作用是       。

③ 检验第4种物质是否存在的实验方案：取D中白色固体于试管中，       。

在国际贸易实务的有关单证中，英语“VIA”后面跟的名词表示目的地，而“IN TRANSIT TO”后面跟的名词则表示中转地。 ( )

帕金森病最常见的首发症状是

A．静止性震颤
B．铅管样强直
C．齿轮样强直
D．慌张步态
E．小步态