问题 问答题 简答题

为什么炼钢中硅氧化反应进行得十分迅速?在碱性炼钢条件下会不会发生硅的还原?为什么?

答案

参考答案:

由于SiO2的分解压力比碳、锰和磷的氧化物的分解压力都低,所以它极易被氧化。在碱性炼钢条件下,由于SiO2能与CaO结合成稳定的硅酸盐,所以碱性渣中SiO2的活度很低,不会发生硅的还原。

阅读理解

The increase in tuition fees has led to a “clear drop” in the number of English students applying for university places this autumn. There are 15,000 “missing” applicants(申请人) this academic year, according to the Independent Commission on Fees. Chairman Will Hutton said: “We’re asking our young men and women to have more debt than any other country in the world — it’s higher than the average debt in the US. It’s not clear whether those lost students this year will return next year, or if it’s a storm warming of a worrying trend.”

But the commission’s report says there does not seem to be an impact on poorer communities. The commission found there was no significant change in the application rate to the key universities, such as Oxford or Cambridge. The decline(下降) in England has not been mirrored(再现) in other parts of the UK where fees have not been raised, and the drop can only partly be explained by falling numbers of young people in the population. Students from Scotland attending Scottish universities do not pay fees, while the Welsh Assembly says it will pay fees above £3,465 for Welsh students attending UK institutions.

The average tuition fee at English universities this year is £ 8,385, rising to £ 8,507 next year. UK and EU students have access to government-backed loans to pay the fees. And the survey of 1,000 pupils aged 15-18, carried out this April, found that the majority expected to go on to higher education as people continue to understand that university remains a good long term investment(投资) in their future.

A spokeswoman at the Department for Business, Innovation and Skills which is responsible for universities, said: “Students shouldn’t be forced to put off going to university for financial reasons. Most students will not have to pay in advance, and no one will have to start paying back their student loan until they start to earn at least £ 2l,000 per year.”

小题1:From the first paragraph, we know that        .

A.the rising tuition fees have a great effect on English students

B.many English students are missing the final examinations

C.the lost English students will find their way back

D.it’s a trend that English students are dropping out of school小题2: Why is there still a drop of applicants though fees have not been raised?

A.Because the students live in poor communities.

B.Because education is free for Scottish students.

C.Because there are less young students in the area.

D.Because Welsh students will pay fees above£3,465.小题3:What’s the students’ attitude to universities in the survey?

A.They will stop applying for university places this autumn.

B.They feel universities takes up too much time.

C.They are anxious to go to a key university.

D.Most of them are willing to go to university.小题4:The spokeswoman in the last paragraph advises students to        .

A.put off going to university

B.pay for the fees in advance

C.reduce the anxiety about the rising fees

D.pay back their loan soon aller graduation

单项选择题