在职申硕英语考试

【单选题】Scraps of food could soon be helping power your home, thanks to an ultra-cheap bacteria-driven battery. Its developers hope that instead of feeding the dog or making garden compost(混合肥料) ,organic household waste could top up your home’s electricity.
Although such "microbial fuel cells" (MFCs)have been developed in the past, they have always proved extremely inefficient and expensive. NowChris Melhuish and technologists at the University of the West ofEngland(UWE、inBristol have come up with a simplified MFC、that costs as little as ￡10 to make.
Right now, their fuel cell runs only on sugar cubes, since these produce almost no waste when broken down, but they aim to move on to carrot power. "It has to be able to use raw materials, rather than giving it a refined fuel," says Melhuish.
Inside the Walkman-sized battery, a colony ofE、coil bacteria produce enzymes that break down carbohydrates, releasing hydrogen atoms. The cell also contains chemicals that drive a series of redox, or reduction and oxidation reactions, stripping electrons from the hydrogen atoms and delivering them steadily to the fuel cell’s anode(正极). This creates a voltage that can be used to power a circuit.
To prove the MFC、works, the researchers are using it to power a small light-sensitive robot.And when a number of the cells are connected in series, they could power domestic appliances, running a 40-watt bulb for eight hours on about 50 grams of sugar.
Earlier MFCs were inefficient because they relied on energy-hungry filters and pumps.By experimenting with different anode materials, the UWE、team have figured out how to make their system work: they dump the bacteria and redox chemicals directly into the cell.
In its current form, the UWE、team says its organic battery can produce eight times as much power as any previous MFC、But Melhuish wants to improve this, both by scaling it up and finding a better mix of redox chemicals.
According to Melhuish, his present MFC、______.A．is of very little use right now

B、is no more efficient than previous ones
C．consumes a lot of organic materials
D．is already considerably efficient

网考网参考答案：D
网考网解析：
在最后一段中有这样一句话the UWE team says its organic battery can produce eight times as much power as any previous MFC(UWE团体说他们的有机电池与从前的MFC电池相比产生的能量要高8倍)，这说明这种型号的MFC效率已经很高了。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>