问题
单项选择题
泥浆泵排出空气包的充气压力一般是排出泥浆压力的：（）.
A、1/3－1/2
B、1/2－1
C、1/3－1
D、0－1/2
答案
参考答案：A
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泥浆泵排出空气包的充气压力一般是排出泥浆压力的：（）.
A、1/3－1/2
B、1/2－1
C、1/3－1
D、0－1/2
参考答案：A
Directions: There are 4 passages in this part. Each of the passages is followed by 5 questions or unfinished statements. For each of them there are 4 choices marked A, B, C and D.
Passage One
| The Warranty Holdings Group, a European leader in mechanical breakdown insurance and a researcher and commentator on trends in motoring, says that the motorists’ world 20 years from now will be marked by more cars, more choice and more technology. Built-in safety features will increase and will include night-vision and collision-avoidance system, and monitoring devices to stop drivers falling asleep at the wheel. A growth in tele-working and home shopping should cut the numbers of trips in a car made by most motorists and "fun" sports cars will become popular as private motoring becomes more recreational in nature. The survey results show that despite years of research into alternative fuel sources for vehicles, no clear winner has emerged for a replacement for the conventional petrol-engined car. Gas and electricity are the best possibilities, with Toyota’s design division in Japan claiming it already has an electric car that will drive up to 250kin on a single charge. However, while electric and "hybrid" powered vehicles will be far more in evidence in the future, it will take a major technological breakthrough to steer the car industry away from its current path of gradual improvements to the petrol-driven internal combustion engine. Professor Garel Rhys, of the Cardiff Business School in Wales, says engine fuel injection systems of the future will be far more frugal than anything that exists at the moment. "It will be like putting a pipette of petrol into the cylinders, rather than just throwing it in by the bucket load, which is almost what we do at the moment when you compare it with what could be possible. " Some environmentalists point to the Twingo, the small car developed by France’s Renault company, to show that what could be achieved by the world’s car industry if it moved away from a trend towards bigger and more powerful cars and radically cut the fuel consumption of its products. Public opinion polls in many countries show motorists wanting access to this kind of environmentally-aware car. A prototype environmental car, the SMILE (smaller, intelligent, lighten, efficient) has been put together by the environmental group Greenpeace. The group hopes the concept will catch on. It depends heavily on supercharging or forcing fuel mixture into the cylinders at higher than normal pressure. Some experts say this is a good way to extract high performance and high fuel efficiency from small engines. Cutting the fuel consumption has had no negative effect on the handling or performance of the car, according to the designers. Top speed, flexibility and acceleration from the engine is as good or better than the original Twingo. They say the technology used to create the Twingo SMILE could just as easily be used on other brands of car. What remains to be seen is whether the enthusiasm of environmental designers catches on with the dollar-driven international car industry, and whether motorists back up with their chequebooks their desire for "greener" cars. |
It can be inferred from the passage that ______.
A．it is unlikely that today’s petrol-driven car will be a thing of the past in the near future
B．electricity will soon be the alternative fuel source as Toyota has succeeded in designing an electric car
C．the car industry has attempted to make a breakthrough in improving the petrol-driven engine but failed
D．the car industry is now trying to economize its current engine fuel injection systems and make the cars more powerful