R是指。（） A.扬声器的电功率 B.扬声器到听音乐的距离 C.空间某点的高压级 D

说明等离子燃烧系统检修工艺。

肺末梢组织充气过度导致（）

A.肺气肿

B.肺不张

C.肺水肿

D.肺脓肿

E.肺褐色硬化

Windows98中的文件管理系统从逻辑结构上看，大致分为三个层次：第一层是可安装的文件系统管理器，第二层是各种文件系统，第三层是　【 】　。

在没有特别说明的情况下，通货膨胀一般是用消费者价格指数(CPI)衡量的物价涨幅，这主要因为CPI是根据一国消费者最终消费支出的商品种类和权重编制的价格指数，该指数最直接地影响居民收入的真实购买力。政府从维护居民福利的角度看，没有哪个价格指数比CPI更合适、更体贴民意了。而食品价格波动主导了中国的消费者价格指数波动，这不仅因为食品价格在商品篮子中占超过三成以上的比重，更重要的是食品价格本身波动剧烈，故而关注食品价格波动成为研究中国通货膨胀的重中之重。对这段文字概括最准确的是：

A．说明在中国食品价格为何成为研究通胀问题的焦点

B．分析控制食品价格波动对中国国计民生的意义

C．解释食品价格波动如何对消费者价格指数产生影响

D．强调提高居民的真实购买力应从控制食品价格入手

If there is one thing scientists have to hear, it is that the game is over. Raised on the belief of an endless voyage of discovery, they recoil from the suggestion that most of the best things have already been located. If they have, today’s scientists can hope to contribute no more than a few grace notes to the symphony of science.

A book to be published in Britain this week, The End of Science, argues persuasively that this is the case. Its author, John Horgan, is a senior writer for Scientific American magazine, who has interviewed many of today’s leading scientists and science philosophers. The shock of realizing that science might be over came to him, he says, when he was talking to Oxford mathematician and physicist Sir Roger Penrose.

The End of Science provoked a wave of denunciation in the United States last year. "The reaction has been one of complete shock and disbelief, "Mr. Horgan says.

The real question is whether any remaining unsolved problems, of which there are plenty, lend themselves to universal solutions. If they do not, then the focus of scientific discovery is already narrowing. Since the triumphs of the 1960s—the genetic code, plate tectonics, and the microwave background radiation that went a long way towards proving the Big Bang—genuine scientific revolutions have been scarce. More scientists are now alive, spending more money on research, that ever. Yet most of the great discoveries of the 19th and 20th centuries were made before the appearance of state sponsorship, when the scientific enterprise was a fraction of its present size.

Were the scientists who made these discoveries brighter than today’s That seems unlikely. A far more reasonable explanation is that fundamental science has already entered a period of diminished returns. "Look, don’t get me wrong," says Mr Horgan. "There are lots of important things still to study, and applied science and engineering can go on for ever. I hope we get a cure for cancer, and for mental disease, though there are few real signs of progress.\

John Horgan（）.

Ⅰ. has published a book entitled The End of Science

Ⅱ. has been working as an editor of Scientific American

Ⅲ. has been working many years as a literary critic

Ⅳ. is working as a science writer

A. Ⅰ and Ⅱ

B. Ⅰ

C. Ⅰ and Ⅳ

D. Ⅰ, Ⅱ and Ⅳ