实现VPN的关键技术主要有隧道技术、加/解密技术、 (9) 和身份认证技术。如果需要

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问题:

实现VPN的关键技术主要有隧道技术、加/解密技术、 (9) 和身份认证技术。如果需要在传输层实现vPN,可选的协议是 (10)

A.L2TP
B.PPTP
C.TLS
D.IPSec

考点:计算机软件水平考试高级系统架构设计师系统架构设计师
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急性前列腺炎的表现是

A.少尿伴肾绞痛
B.少尿伴心悸气促、胸闷不能平卧
C.少尿伴大量蛋白尿、水肿、高脂血症和低蛋白血症
D.少尿伴排尿困难
E.少尿伴乏力纳差、腹水、皮肤黄染

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把2mol碳在1.5mol氧气中燃烧,恰好完全反应。燃烧后的产物中既有CO2也有CO,则生成的CO2和CO总的物质的量是

A.1.5mol

B.2mol

C.1mol

D.大于1.5mol,小于2mol

题型:单项选择题

下列对国务院的认识,正确的是(   )

A.它是国家最高权力机关

B.它是最高权力机关的执行机关

C.它是我国重要的国家机构,拥有制定法律的权力

D.它与其他国家机关的关系是监督与被监督的关系

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培训课程的基本要素包括()

A.课程目标

B.教学模式

C.教学策略

D.课程评价

题型:单项选择题

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

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