题目内容
Activities in environments that pose great danger to humans, such as locating sunken ships, cleanup of nuclear waste, prospecting for underwater mineral deposits, and active volcano exploration, are ideally suited to robots. Similarly, robots can explore distant planets. NASA's Galileo, an unpiloted space probe, traveled to Jupiter in 1996 and performed tasks such as determining the chemical content of the Jovian atmosphere.
Robots are being used to assist surgeons in installing artificial hips, and very high-precision robots can assist surgeons with delicate operations on the human eye. Researehin telesurgery uses robots, under the remote control of expert surgeons that may one day perform. operations in distant battlefields.
Robotic manipulators create manufactured products that are of higher quality and lower cost. But robots can cause the loss of unskilled jobs, particularly on assembly lines in factories. New jobs are created in software and sensor development, in robot installation and maintenance, and in the conversion of old factories and the design of new ones. These new jobs, however, require higher levels of skill and training. Technologically oriented societies must face the task of retraining workers who lose jobs to automation, providing them with new skills so that they can be employable in the industries of the 21st century.
Automated machines will increasingly assist humans in the manufacture of new products, the maintenance of the world's infrastructure, and the care of homes and businesses. Robots will be able to make new highways, construct steel frameworks of buildings, clean underground pipelines, and mow lawns. Prototypes of systems to perform. all of these tasks already exist.
One important trend is the development of micro-electromechanical systems, ranging in size from centimeters to millimeters. These tiny robots may be used to move through blood vessels to deliver medicine or clean arterial blockages. They also may work inside large machines to diagnose impending mechanical problems.
The author wants to tell us in the Para 1-3_____.
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First it was tulips, then it was shares in the South Sea Company. Now the dot. coms have been added to that dubious hall of fame-the problems in the financial markets.
Yesterday (Fri) yet another high profile dot.com business-Letsbuyit-announced it had run into difficulties.
The madness for technology stocks in 2000 had all the ingredients that investors knew little about, greed for money, an economy firing on all cylinders, some dashing young entrepreneurs andeven the rules of business had been rewritten.
Yet what it did not have was the ability to rewrite the rules of economics. When the historians come to write the story of the dot. com bubble, their epitaph will be the same as that London in 1720 or Wall Street in 1929: it wasn't different this time. In vain did the Cassandra foretell that it would all end in tears, that there were Simply too many companies chasing too little revenue, and that for the stock market valuations of the dot.coms to be justified every person on earth would have to be surfing the net 24 hours a day with a mobile phone clamped to each ear.
Most dot.coins were destined to be squeezed by cut-throat competition. Reality has now set in. Shares in dot.com start-ups that were changing hands for hundreds of dollars each at the height of the speculative fever are now virtually worthless. Did anybody know or care what Engage Inc was actually involved in, let alone have any idea of its likely earnings potential when it was trading at US dollar 95 a share earlier this year. They probably took a closer look as the shares fell to just over US dollar 1 this month.
However, there was little analysis of this sort as the year dawned with the US economy booming, fears of a millennium bug meltdown and the merger between America Online, the world's biggest internet services provider, and Time Warner, one of biggest traditional media companies, symbolizes the unstoppable force of the "new example".
The combination appeared to mark the coming of age of online upstarts as AOL had all the potential, but Time Warner was making all the money.
Having risen a record-breaking 88% in 1999, the Nasdaq composite index of technology companies rallied even higher in the first three months of 2000. On March 10, the index reached a record high of 5048. In the dying weeks of the year, it is trading at less than half this level. With the bubble burst and investor confidence in tatters, the index has recorded its worst ever annual performance in its 29-year history. The previous low of a 35% decline was recorded during the oil crisis of 1974.
This year's bear market began in April, when the Nasdaq suffered four of its worst ever points losses in quick succession. Within 51 trading days, US dollar 2,400bn had been wiped from the technology-driven stock market.
The rate of company closures is still accelerating, according to a report published by Webmergers, an online consultancy. In the first 11 months of the year, 130 internet companies folded with about 8,000 job losses.
In spite of signs that the stock market madness has come to an end, most analysts believe the internet will make a lasting impact on business and the economy.
Andy Grove, chairman of Intel, confidently predicted last year: "There won't be any internet companies [within a few years]. All companies will be internet companies, or they will be dead." This is almost certainly true. The Wall Street crash of 1929 did not mean the end of radio or prevent the spread of the motor car. But a word of warning. In real terms, the S&P composite index did not regain its level of September 1929 until December 1958.
The main idea of the passage is that_____.
从环境保护出发，对工程建设项目进行合理的选址和选线主要是指（)。A．选址选线地区的环境特征和环境从环境保护出发，对工程建设项目进行合理的选址和选线主要是指()。
关于富营养化，下面说法中错误的是（)。A．湖泊中总磷与叶绿素a和透明度之间存在一定的关系B．Carlson关于富营养化，下面说法中错误的是()。
收入乘数的驱动因素比市净率的驱动因素多销售净利率。 ()
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