问题 单项选择题

电解法处理含铬废水,以下描述不正确的是( )。

A.阴极氢离子获得电子,生成氢气
B.阳极铁电极被氧化,六价铬被还原成三价
C.阴极直接将六价铬还原为三价铬的作用最强
D.碱性条件下,三价格还原成氢氧化铬形式沉淀

答案

参考答案:C

解析: 正确答案为C。

阅读理解

Here is some news of the future.

March 20. 2035

There was a lot of news around the life extension drugs that hit the market a decade ago. They didn't promise that you would live forever. but they gave you a chance to extend your life an extra five to ten years. Even though the life expectancy rate at birth has increased greatly. the life expectancy for seniors hasn't improved that much. Basically. you have a greater chance to become a senior, but you will not have a much longer lifespan, and this is where the anti-aging drugs intend to kick in. So ,do the anti-aging drugs work? Well.  it is too early to tell. But the sales so far are very good.

April 19, 2035

Of the total US population of 378 million, people over 65 years of age now make up 20% for the first time. The senior ratio was only 4.1% by year 1900. and l2.4% 30 years ago.

The number of people above 65 compared to those of what is considered working ages. between 15 and 64. is currently 33.7%. This is up from l85% since year 2005. which means that for every retired person there are now two workers. compared to four workers 30 years ago. The number of people above the age of 80 has grown t0 23.8 million; making them 6.3% of the total population compared t0 3.6% in 2005.

April 12. 2040

Although introduced in the market only five years ago, 10% of all hydrogen fuel now sold in the US is of the environmentally friendly Re-Hydro label, produced through. eletrolysis  (电解) based on a source of 1OO% renewable energy. Several producers have turned to producing Re-Hydro. mainly because of lower tax. which also keeps the price of. Re-Hydro on the same level as regular  hydrogen. Most analysts believe that Re-Hydro will be the .dominating fuel in the future

小题1:The sales of the life extension drugs so far clearly show that         .

A. people have no faith in them        

B people want to give them a try

C. they work very well for seniors      

D. they have no effect on people's health

小题2:What can we learn from News 2?

A.Many Americans will find it hard to find a job .

B.It's very hard for seniors to pass the age of 80.

C.The US population has been increasing rapidly since 2005.

D.The US population has been aging rapidly since 2005.小题3:We can know from the passage that the fuel of the Re-Hydro label is______.

A. expensive           B cheap            C.green           D. dangerous

小题4:What can we infer from News 3?

A.Re-Hydro will be widely used in the future.

B.The government discourages the production of Re-Hydro.

C.Producers are not interested in producing Re-Hydro.

D.Re-Hydro is more expensive than regular hydrogen.

单项选择题