hellosnow.
英语科普文章选——2004年十大科学发现 不久前，著名的《科学》杂志评选出2004年最重要的十大科学发现。这些发现中既有人类对神秘宇宙太空的探索，也有对身边熟悉事物的新发现。无论是何种的科学探索和发现，人类求知的愿望和动力永远都在推动社会的发展和进步。 Water and robots on Mars chosen as tops in 2004 by 'Science'WASHINGTON — The conclusive discovery by a pair of wheeled robots that Mars once had vast pools of water and possibly could have harbored life was chosen by the editors of the journal Science as the most important scientific achievement of 2004. Scientists announced in March that the Mars once played host to salty seas. This Mars Express image indicates water erosion. NASA's two Mars rovers（漫游者）Opportunity and Spirit, landed on the Red Planet early in 2004 and have since found clear and conclusive evidence that Mars was drenched with（浸透） water at some time in its history. The editors of Science, one of the world's leading publishers of peer-reviewed, original research, judged the robotic accomplishment as the top scientific "Breakthrough of the Year." "Inanimate, wheeled, one-armed boxes roaming another planet have done something no human has ever managed," Science reported in this week's edition. "They have discovered another place in the universe where life could once have existed." Nine other scientific achievements, including discovery of another species of human, were selected as runners-up, but Science editor-in-chief Donald Kennedy said "there wasn't much doubt about this year's winner." Opportunity and Spirit found unmistakable proof of Martian water: rippled sediments（沉积物） that were once at the bottom of a shallow sea, and rock that once was so water-soaked that "it had rotted," the journal said. "Their finds mark a milestone in humankind's search for life elsewhere in the universe," Science said. Kennedy said one of the most important messages from the remote exploration is "the extraordinary efficiency of these robot missions." He said it is clear that the National Aeronautics and Space Administration must not abandon its robotic exploration while gearing up for President Bush's program to send humans to the moon and later to Mars. "To do one at the expense of the other would be a mistake," Kennedy said. "It remains to be demonstrated what a human exploration could do that we can't do now or couldn't do in the next 10 years with robotic technology." The first runner-up for breakthrough of the year was the discovery on the Indonesian island of Flores of fossils from a species of tiny humans who stood about 3 feet tall and had a brain less than a third the size of modern humans. Yet, the diminutive（小的） hominid（原始人） lived about 18,000 years ago. This suggests that Homo floresiensis shared the Earth with Homo sapiens（人类）, or modern people. Science said some described the find as "the biggest discovery in half a century of anthropological research."Third on Science's list of 2004 breakthroughs was the cloning of human embryos by South Korean researcher Woo San Hwang and his colleagues. The work was not an attempt to genetically duplicate a human. Instead, the researchers hoped to make embryonic stem cells for research purposes. Although many other mammals have been cloned, the work was the first to demonstrate that cloning techniques would work with human cells. Following are the rest of Science's 2004 selections. 4. U.S. and Austrian scientists created a new form of condensate（冷凝物）, an ultracold gas that slips into a quantum state where a group of atoms act as a single superatom. The achievement was notable because it used fermions（费米子）, a class of atoms with a nuclear structure that makes it difficult to create a condensate.5. Scientists discovered that "junk DNA," the base pairs between known genes in the human genetic structure, play an important role. Several research teams have found that DNA between genes helps determine how vigorously and often the genes are activated and shapes the coding for protein production. 6. Astronomers discovered a pair of neutron stars（中子星） locked in orbit of each other and spewing out beams of radiation. Both objects are pulsars（脉冲星）, rapidly flickering on and off with pulses of energy. One object is pulsing at the rate of 44 times a second. By studying the radiation, astronomers hope for the first time to learn about the density of matter within a neutron star. 7. Naturalists tracking the fate of wild species worldwide reported bad news. A survey of amphibians（两栖动物） found that of 5,700 known species, about 30% were at risk of extinction. A survey in the United Kingdom found that butterflies, songbirds and native plant species are all losing ground in the battle for species survival. 8. It is one of the most common and universally known substances, but researchers are still learning more about water. Several teams of researchers made new discoveries about how water molecules（分子） bind together and how electrons（电子） and protons（质子） dissolve in water. Some of the findings are questioned and Science noted: "Water still gives researchers much to scratch their heads about." 9. A new form of research and aid is creating "a revolution in public health," said Science. The partnership of public and private organizations worldwide is changing the way drugs are developed, tested and distributed to the poorest nations on Earth, the journal said. Researchers tallied at least 92 public-private partnerships worldwide attacking such diseases as malaria, tuberculosis and HIV. 10. Researchers have developed techniques to identify genes in ocean water or in specimens recovered from deep underground. Thousands of new genes have been found. By sequencing these genes, researchers hope to identify news species and, perhaps, learn how organisms survive in harsh and forbidding locations on Earth.
monica的私人花园
The Internet is a giant network of computers located all over the world that communicate with each other. The Internet is an international collection of computer networks` that all understand a standard system of addresses and commands, connected together through backbone systems. It was started in 1969, when the U.S. Department of Defence established a nationwide network to connect a handful of universities and contractors. The original idea was to increase computing capacity that could be shared by users in many locations and to find out what it would take for computer networks to survive a nuclear war or other disaster by providing multiple path between users. People on the ARPNET (as this nationwide network was originally called) quickly discovered that they could exchange messages and conduct electronic "conferences" with distant colleagues for purposes that had nothing to do with the military industrial complex. If somebody else had something interesting stored on their computer, it was a simple matter to obtain a copy (assuming the owner did not protect it). Over the years, additional networks joined which added access to more and more computers. The first international connections, to Norway and England, were added in 1973. Today thousands of networks and millions of computers are connected to the Internet. It is growing so quickly that nobody can say exactly how many users "On the Net". The Internet is the largest repository of information which can provide very very large network [参考译文] Internet是由位于世界各地相互通信的计算机连接而成的巨大的计算机网络。 Internet是计算机网络的国际性的集合，这些网络都符合具有地址和命令的标准体系，并经骨干网连在一起。Internet始建于1969年，当时美国国防部为连接少数几所大学和协议企业而建立了一个全国性网络。最初的想法是要增加计算机能力并可由许多地点的用户共享，并且通过提供用户间多条路径来找到哪一种计算机网络能够在核战或其他灾难中幸存。ARPNET（这种全国网络最初的名称）上的用户很快就发现他们可以与远距离的同事交换消息，并且进行某种目的的电子“会议”，而这些目的与军事工业企业没有任何关系。如果另外一些人在其计算机中存有有趣的东西，得到其拷贝是很容易的事（假定拥有者没有进行保护）。 几年间，新的网络接入使越来越多的计算机加入进来。在1973年进行了第一次与挪威和英国的国际连接。今天，有成千上万的计算机网络和数百万台计算机与Internet相连。Internet发展如此之快以至于没有人能准确地说出网上有多少用户。 Internet是最大的信息宝库，它可以提供非常巨大的网络资源。这种网络资源可分为网络设备资源和网络信息资源。网络设备资源使我们能够进行远程计算和通信。网络信息资源向我们提供各种各样的信息服务，如科学、教育、商务、历史、法律、艺术和娱乐等等。
