问题 单项选择题

阅读下面这篇文章,回答下列各题。

粒子束武器

粒子束武器大致分为三个主要部分,即由能源、电子喷嘴和集流加速器组成。

能源,一般是靠核裂变或聚变的极高的脉冲功率形成。人们采用专门的核爆炸式的发电机,通过核裂变或聚变释放出大量的能量,发出高压脉冲电流。它通过控制开关和特殊传输线路在一瞬间传输给巨型贮能器,把脉冲电荷堆积起来,通过超高压开关在毫微秒计的时间内放电。

流量压缩装置和电子注入器把脉冲高压转换成电子束,高强电磁场把它在长长的电子枪中加速,通过电子嘴向集流加速器喷射,作为形成和加速质子的媒介。

集流加速器是粒子束的核心。在电子喷嘴和集流加速器之间,装有注入阀,引入Z质(如有一种加速器的Z质用氢气),由于电子束的高速碰撞,电子被剥落,形成质子,并集流加速,最后接近光速发射出来,摧毁目标。

粒子束武器的简单工作过程是:通过核裂变或聚变的形式实现爆炸或脉冲发电,以产生高功率的脉冲粒子束,这些粒子束以接近光速的速度射向目标,击毁目标。

(选自《自然科学》14辑)

根据文意,下列判断不正确的是()。

A.通过核裂变或聚变的形式实现脉冲式发电,是粒子束武器获取能源的常用的方式。

B.形成和加速质子的媒介是脉冲高压电转换成的电子束。

C.集流加速电子束以接近光速发射出来,就能摧毁目标。

D.脉冲高压在流量压缩装置和电子注入器中转换成电子束。

答案

参考答案:C

解析:

考查对文章局部内容的理解和分析能力,主要涉及对同一内容作不同方式叙述的语言形式的认知。本题提供的选项,陈述的对象变化了。解题首先要理解原文和能把选项与原文句作比较,选出错项。A项涉及的文中原句以粒子束武器的“能源”为陈述主体,改造成选项后以“脉冲式发电”为陈述对象,且将“一般”一词表述为“常用”;B项在文中的原句附加成分很多且为“把”字句,改造成选项后,陈述对象由“电子束”变为“媒介”;D项在文中原句中为“把”字句,改为选项后陈述对象变为“脉冲高电压”。以上都是考查用不同的语言形式表述同一意思的修辞能力。答案是C项,它错误地改变了原句“由于电子束的高速碰撞,电子被剥落,形成质子,并集流加速,最后接近光速发射出来,摧毁目标”的内容,意思与原文相悖。

阅读理解

阅读理解。

     The A-level question Have 22 continuous years of rises in A-level pass rate made the exam worthless? David Miliband, the minister for School Standards, insists the answer is a firm "no". And he said it was

wrong that "more will mean worse and more education for more people will mean lower standards".

Figures show that - despite the rise in A-grades to 21. 6 per cent - only 22,000 out of 600,000

18-year-olds gain three A-grade passes. Put another way, that means - in a primary class of 30 pupils -

only one will get three A-grades. The center right Bow Group, in a pamphlet published today, however,

says nine out of ten scholars believe A-grades have been devalued over the past ten years

     Two inquiries (调查) - both set up by the Government's exams watchdogs - one of which included

independent teaching experts, refused to accept that there had been any "dumping down" of A-level

standards. But while they conclude that the exam questions have not become easier, changes in examining methods have almost certainly made it easier to gain top-grade passes.

     As a result of the exams shake-up introduced in 2000, students sit six different types of exams to make up an A-level during the course of their two years of study. Only 20 per cent of the marks are set for the

end-of-term exam. This makes it easier for teachers to help their pupils with the right answers.

     Mr Miliband said yesterday, "My argument is not that today's generation of pupils are cleverer than

their parents; it is that schools and teachers are getting better at getting the best out of them."

1. From the writer's point of view, the rise in A-grades to 21. 6 per cent shows _____.

A. it is generally thought more education means lower standards

B. the rise in the A-level pass rate has made the exam worthless

C. the quality of the 18-year-olds has become lower

D. it is still hard for the general pupils to get three A-grade passes

2. The underlined word "they" in the second paragraph refers to _____.

A. the exams watchdogs

B. the independent teaching experts

C. the A-level standards

D. the two inquiries

3. As a result of the exams shake-up introduced in 2000 _____.

A. the pass rate for A-levels was set to rise continuously

B. the exam became easier than it had been before 2000

C. pupils could have many more choices of test after 2000

D. it soon became popular with teachers and pupils

4. What does this passage mainly discuss?

A. How reliable and effective the A-level grading system is.

B. How the A-level system helps universities select pupils.

C. How the pass rate has been increased in recent years.

D. How the A-level grading system has changed over the years.

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