填空题Nikola Tesla invented alternating current technology that enabled electricity to be transmitted over long distances.____

Possible phase relationships between voltage and current in an alternating current circuit include which of the following conditions?（）

Fuel Cells: 21st Century Electricity　　The 21st century’s leading energy source may very well depend on the development of a technology that was first discovered in 1839. Indeed, many experts believe that the future of electricity generation will not come from further refinement of solar, wind, coal or nuclear energy, but from fuel cells. Among the various types of fuel cells, the ceramic or solid oxide fuel cell promises to achieve the greatest efficiency of conversion of fossil fuels such as gas and coal to electricity while producing only very low levels of pollutants. To this end, a consortium comprising five leading organizations has established Ceramic Fuels Ltd, initially to expand fuel cell research and development and secondly, to bring the technology to commercial application.　　Ceramic fuel cells are electrochemical devices that directly convert fuels such as gasified coal or natural gas into electricity without the limitation of the Carnot cycle (an ideal thermodynamic cycle in which heat is taken onto a working fluid at a constant upper temperature and rejected at a constant lower temperature). In many respects, fuel cells work like batteries. As long as they are constantly supplied with fuel and oxidant, fuel cells can continuously produce power, removing the need for recharging.　　Fuel cells offer several advantages over traditional thermal power plants. The major difference between these two power generators is that the chemical energy of the fuel cell is converted directly to electrical power without intermediate conversion first to heat. The efficiency of a coal-fired thermal plant is typically in the range of 30%-35%. In a combined cycle gas turbine system running on natural gas, the maximum efficiency is in the range 45%-50%. Many experts believe high temperature fuel cells could reach efficiencies of 80%-85%. Ceramic fuel cells thus offer a more efficient and less polluting alternative to current power generation technologies.　　By-products from fuel cells are high quality heat, carbon dioxide and steam. The temperature of the exhaust gases is well above 500℃, meaning that solid oxide fuel cells are very attractive for electricity and heat generation as, in addition to supplying electricity, the leftover amounts of heat created during the process could be used to produce heat for industries, provide hot water supplies or warm buildings.　　Fuel cell technology is not new. In fact, the principles of fuel cell operation were first reported by British scientist Sir William Grove in 1839. His prototype used dilute sulphuric acid and operated at room temperature. Ceramic fuel cells developed much later, with the first one operating at 1000°C in 1937.　　Ceramic fuel cells offer many advantages over other energy systems:　　● they have the potential to produce electricity efficient from several fuel sources　　● they can generate large amounts of electricity　　● they are relatively quick to install　　Fuel cell research and development is extremely competitive worldwide, with the USA, Japan and some European countries leading the charge to commercialize this promising technology. For instance, a Dutch Belgian company has developed a fuel cell for a Volkswagen van and is also working on a larger unit to power a bus. Additionally, a German company is working on a fuel cell for the European space shuttle program and for submarines, while a Canadian company is evaluating a fuel cell to be used in small buses.　　Recent reports point to promising large international markets for ceramic fuel cells. Prospects for fuel cells in South East Asian markets appear good. Several countries, including Indonesia, Thailand and The Philippines are expected to demonstrate high rates of growth in demand for power an encouraging situation for those countries quick enough to develop and commercialize fuel cell technology.　　Energy is a vital component of a technology-based society and the growing need for electricity generation by the most efficient method will ensure a promising future for ceramic fuel cell technology. The Ceramic Fuel Cells Ltd initiative represents a major collaborative venture between public and private sectors. It is envisaged that this venture will go a long way towards achieving a greater efficiency of energy use worldwide.　　Do the following statements reflect the claims of the writer in the Reading Passage?　　YES　　　　　　　　 if the statement reflects the claims of the writer　　NO　　　　　　　　 if the statement contradicts the claims of the writer　　NOT GIVEN　　　　 if it is impossible to say what the writer thinks about this　　Statements:　　1．Sir William Grove was a physicist.　　2．Future transport vehicles may be powered by fuel cells.　　3．European companies were first in the race to develop fuel cell technology.　　4．Some rapidly developing South East Asian countries will soon market fuel cells.　　5．Cooperation between private companies and governments will encourage wider use of efficient energy sources.

（）is electricity that is flowing where it’s not supposed to through water, fittings on your boat, wet wood, damp surfaces, etc.

The Owners to take over and pay all fuel remaining in the Vessel’s bunkers on re-delivery at current price at the port of redelivery，or at the nearest main bunkering port，if the bunker price at the port of redelivery is not available. This indicates that the Owners are to take over and pay the remaining bunkers（）.

过流（Over Current）故障

What is implied in the first sentence?

Nikola Tesla invented alternating current technology that enabled electricity to be transmitted over long distances.____

The alternating current generator supplying a load has a voltage drop resulted from the loadWhen the load has a lagging power factor this voltage drop （）.

You are the network consultant from passguide.com. You have been asked for which two features of optical networks allow data to be transmitted over extremely long distances? （）

What two descriptions best define DWDM？ （）

In an alternating current electrical system, a low system power factor is a direct sign of （）

The frequency of the alternating current generated by a synchronous generator is governed by the speed and the（）

Many great scientists and inventors of the past, such as Nikola Tesla, has possessed the ability of extraordinary, visualization skills that enabled them to analyze the most minute details of complex machines before the devices were even constructed.

Which of the following components are used to convert alternating current produced in the generator windings to direct current?（）