题目内容
发行涉及国有股的，应在国家股股东之后标注()，在国有法人股股东之后标注()，并披露前述标志的依据及标志的含义。
查看答案
搜索结果不匹配？点我反馈
更多问题
关于MM的无公司税模型命题一错误的是()
But, while inventions make a global network possible, it takes human cooperation to make it happen. Standage's insight in this regard adds depth to his technological history. It underscores the relevance to our own time of the struggles of Samuel Morse in America, William Cooke in England, and other telegraph pioneers. They made the technology work efficiently, sold it to a skeptical public, and overcame national and international bureaucratic obstacles. The solutions they found smooth the Internet's way today.
Consider a couple of technical parallels. Telegrams were sent from one station to the next, where they were received and retransmitted until they reached their destination. Stations along the way were owned by different entities, including national governments. Internet data is sent from one server computer to another that receives and retransmits it until it reaches its destination. Again the computers have a variety of owners.
Then there is the social impact. The Internet is changing the way we do business and communicate. It makes possible virtual communities for individuals scattered around the planet who share mutual interests. Yet important as this may turn out to be, it is affecting a world that was already well connected by radio, television, and other telecommunications. The Associated Press, Reuters, and other news services would have spread the Star report quickly without the Internet. In this respect, the global telegraph network was truly revolutionary. The unprecedented availability of global news in real time gave birth to the Associated Press and Reuters news services. It gave a global perspective to newspapers that had focused on local affairs. A provincialism that geographical isolation had forced on people for millennia was gone forever. Some seers naively hailed this as a force for world peace. They predicted that tensions over cultural and ethnic differences would relax as people interacted in real time. Visionaries say the same about the Internet. While communications can smooth this process, they do not automatically make it happen. As the experience of the past century and a half has shown, peace takes the will to make it work and sustained effort by all parties.
What does "the gem of late 20th century technology" refer to？
It can be inferred from the passage that a vehicle specifically designed to use methanol,
Although recent years have seen substantial reductions in noxious pollutants from individual motor vehicles, the number of such vehicles has been steadily increasing. Consequently, more than 100 cities in the U. S. still have levels of carbon monoxide, particulate matter, and ozone that exceed legally established limits. There is a growing realization that the only effective way to achieve further reduction in vehicle emissions — short of a massive shift away from the private automobile — is to replace conventional diesel fuel and gasoline with cleaner-burning fuel such as compressed natural gas, liquefied petroleum gas, ethanol, or methanol.
All of these alternatives are carbon-based fuels whose molecules are smaller and simpler than those of gasoline. These molecules burn more cleanly than gasoline, in part because they have fewer, if any, carbon-carbon bonds, and the hydrocarbons they do emit are less likely to generate ozone. The combustion of larger molecules, which have multiple carbon-carbon bonds, involves a more complex series of reactions. These reactions increase the probability of incomplete combustion and are more likely to release uncombusted and photochemically active hydrocarbon compounds into the atmosphere. On the other hand, alternative fuels do have drawbacks. Compressed natural gas would require that vehicles have a set of heavy fuel tanks — a serious liability in terms of performance and fuel efficiency — and liquefied petroleum gas faces fundamental limits on supply.
Ethanol and methanol, on the other hand, have important advantages over other carbon-based alternative fuels: they have a higher energy content per volume and would require minimal changes in the existing network for distributing motor fuel. Ethanol is commonly used as a gasoline supplement, but it is currently about twice as expensive as methanol, the low price of which is one of its attractive features. Methanol's most attractive feature, however, is that it can reduce by about 90 percent the vehicle emissions that form. ozone, the most serious urban air pollutant.
Like any alternative fuel, methanol has its critics. Yet much of the criticism is based on the use of "gasoline alone" vehicles that. do not incorporate even the simplest design improvements that are made possible with the use of methanol. It is true, for example, that a given volume of methanol provides only about one-half of the energy that gasoline and diesel fuel do: other things being equal, the fuel tank would have to be somewhat larger and heavier. However, since methanol-fueled vehicles could be designed to be much more efficient than "gasoline alone" vehicles fueled with methanol, they would need comparatively less fuel. Vehicles incorporating only the simplest of the engine improvements that makes methanol feasible would still contribute to an immediate lessening of urban air pollution.
The author is primarily concerned with ______.
微信支付 
支付宝支付