问题 填空题

有物质A、B、C、D,其有关转化关系如下:

(1)

(2)

已知B为浅绿色溶液,向B溶液中滴加BaCl2试液可生成一种不溶于稀硝酸的白色沉淀.C和D均为单质.试推断:A为______,B为______.

答案

B为浅绿色溶液,说明含有亚铁离子,是A和酸反应产生的,因此A是金属铁,铁和酸反应产生氢气,因此单质D是氢气;向B溶液中滴加BaCl2试液可生成一种不溶于稀硝酸的白色沉淀,因此是硫酸钡沉淀,说明B是硫酸亚铁;铁和盐溶液反应产生硫酸亚铁和单质C,因此该盐溶液中的金属活动性比铁弱,因此可以使铁和硫酸铜反应产生硫酸亚铁和铜,因此A为铁,B为硫酸亚铁,

故答案为:Fe;FeSO4

阅读理解

阅读理解。

     Sixteen-year-old Karlos Dearmans's future is looking much brighter than be might have imagined.

"I've always been into bikes, but never thought I'd end up working with them," he says. "This scheme

has changed my life." 

     Karlos is learning to refurbish (翻新) old bicycles in the workshop of ReCycle Bikes, a local community

(社区) charity in Sheffied, which has a contract with the city council to provide training opportunities for

young people aged 14 to 16, particularly those dropping out of school.

     "It's about engaging youngsters with education and you thtraining by teaching them work and life skills,"

explains Des Pearce, workshop training manager. "These young people have so much potential, but often

don't realize it."

     Established in 2001, ReCycle Bikes repairs bicycles donated by the public, which, once restored, are

sold for £20. Abandoned bikes supplied by the council ensure a steady flow of bikes, but a recently

formed partnership with Sheffield University should improve further the prospects of the young mechanics.   

     "The student population presents a large and ready market," says Pearce. "So we approached the

university last year and offered to host bike sales on the campus. They thought it was a great idea, and

agreed to supplement our council funding. This means we can train youngsters to repair extra 500 bikes

over three years."   

     Having set up ReCycle Bikes on his own, Pearce now has the staff and resources to track the career

development of those who have passed through his workshop. "However, in the past we depended on

the evidence of personal accounts from the schools because of lack of human and material resources,"

he says.   

     That most of the teenagers enjoy the work is, according to Pearce, easily explained. "Most kids have

ridden a bike and know how to oil a chain or mend a puncture. As low-cost transport, cycling gives the

young and old a sense of freedom and independence, and the impact on their well-being is immense. Add

to that a growing concern for the environment, and it's no surprise that bike sales are on the increase."

1. What do we know about ReCycle Bikes?

A. It is a popular brand of bikes which are sold in Sheffield.

B. It is a local community charity that provides training opportunities for reenagers.

C. It is a contract signed between a local community charity and the city council.

D. It is a training program offered by the city council to those excluded from school.

2. How did ReCycle Bikes run at the beginning?

A. By repairing bicycles donated by the public and selling them.

B. By donations from the public and Sheffield University.

C. By selling bicycles supplied by the city council.

D. By tuition fees from kids aged between 14 and 16.

3. ReCycle Bikes has formed a partnership with Sheffield University because ____.

A. students at Sheffield University assure a large and ready market

B. Sheffield University offers many mechanical teachers to ReCycle Bikes

C. heffield University donates a lot of money to ReCycle Bikes

D. teenagers at ReCycle Bikes can study at Sheffield University

4. ReCycle Bikes depended on information from the schools in the past because ____.

A. the schools could give accurate information  to improve its service

B. students disliked telling the truth when asked about  their personal ideas

C. ReCycle Bikes didn't have the ability to track students'  career development

D. most of the training organizations did it this way at that moment

单项选择题