轴承钢在各钢类中是检验项目最多的钢类。

生物体的结构与其功能是相适应的，下列结构特点不与家兔食草生活相适应的是（　　）

A．犬齿发达

B．消化管长

C．盲肠发达

D．臼齿发达

小丫在探究CO₂与NaOH溶液反应的实验中，先用铝制易拉罐收集满一罐CO₂气体，然后迅速向其中加入一定量的NaOH浓溶液，立即将易拉罐口封闭（不漏气），轻轻摇动易拉罐，发现易拉罐很快变瘪，但过一段时间后，易拉罐又重新鼓起来（反应过程中温度的变化忽略不计）．

【讨论】小丫认为易拉罐变瘪，说明CO₂与NaOH溶液发生反应；小敏此结论不合理，还需进一步验证，验证方法是______；易拉罐为什么又后鼓起来？是不是反应又产生了气体，该气体的成分？

【提出猜想】a．可能是CO₂；b．可能是______．

【查阅资料】①Na₂CO₃具有较强的热稳定性，只有在高温条件下才会分解；

②铝不仅与酸反应，还能与碱溶液反应2Al+2NaOH+2H₂O═2NaAlO₂+3X↑

【实验验证】

①将易拉罐口打开，迅速用燃着的木条伸入罐口，发出“噗”的一声，产生淡蓝色火焰，片刻后熄灭．证明猜想______成立；

②取少量铝片于试管中，先加入适量的水，无明显变化．片刻后再加入少量的氢氧化钠浓溶液，产生气泡．该步实验的目的是______；

【结论】CO₂与NaOH反应的化学方程式是______；

【反思与应用】在生活中铝制容器不能用来盛装酸性物质，也不能盛装______物质．

阅读理解

     It is very possible for a person with a disability to get a job. Depending on the type of disability a

person has, there are many positions available. Of course, he must be realistic in choosing a job. If he has a physical disability, he should look for a job in which he can use his skills and abilities.

     Some larger companies have programs for hiring people with disabilities. It is a good idea to get into

touch with them, as they are much more enthusiastic to hiring people with disabilities due to their positive

past experiences. Some disability-support groups may have lists of companies that have been helpful in the past, have a history of hiring disabled people or know of some working positions that are open to disabled people.

     When talking with an employer about the job, one must be very honest. He should tell the employer

about his disability. It is also important to know whether there are any sorts of' tools or new technology

that could help a person with a disability do a job. For instance, when working with computers, there is

special software that allows one to tell it what to write instead of having to type it. Or a new type of

wheelchair that allows one to do his job easier would also be a very good investment as it may be the key

to getting a job. It is very important for a disabled person to realize that he should not suffer mistreatment

of any kind from the employer. Although his abilities are slightly different from the majority of other

working people, there is no reason for one to he treated badly. He should ask for a fair salary and fair

treatment.

1. Some companies hire the disabled because they think the disabled        .    

A. ask for less money

B. are equal to others

C. work harder than others

D. are pitiful

2. If a person with disability is asking for a job in a company, he should say           .   

A. nothing about his health

B. something about his demand

C. something about his disability

D. nothing about his family

3. The writer suggests in this passage that         .     

A. modern equipment can help the disabled in their jobs

B. the disabled should spend much money on improving their health

C. companies should provide wheelchairs to the disabled

D. the disabled must learn how to operate computers

4. In the last paragraph the writer advises that the disabled should           .   

A. do easy jobs

B. ask for the same rights as others

C. work shorter time

D. often change their positions

5. What's the best title for this passage?    

A. Larger Companies hiring the disabilities.

B. How to get a job for the disabilities.

C. Honesty is important for the disabilities.

D. The disabilities must be realistic.

如图，一上端开口，下端封闭的细长玻璃管，下部有长l₁=66cm的水银柱，中间封有长l₂=6.6cm的空气柱，上部有长l₃=44cm的水银柱，此时水银面恰好与管口平齐。已知大气压强为P₀=76cmHg。如果使玻璃管绕低端在竖直平面内缓慢地转动一周，求在开口向下和转回到原来位置时管中空气柱的长度。封入的气体可视为理想气体，在转动过程中没有发生漏气。

人们发现，世界上任何一种色彩（除无色彩）都有（）这三方面的性质

A.明度；纯度；色相 

B.明度；调和；色相 

C.调和；色相；纯度 

D.纯度；色相；调和