题目内容

胃肠减压护理不正确的是

A. 患者应禁食
B. 保持减压管通畅
C. 胃管堵塞禁止冲洗
D. 注意口腔护理
E. 记录吸出液的量及性质

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寿命周期长是房地产最重要的一个特性。 ( )

A. 对
B. 错

输尿管生理狭窄最窄的部位在

A. 肾盂输尿管交界处
B. 输尿管起始部
C. 与髂动脉交叉处
D. 进入膀胱壁处
E. 跨过骨盆入口处

下列X线所见乳突类型,属于异常的是

A. 气化型
B. 板障型
C. 硬化型
D. 混合型
E. 以上都不是

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. Now Chris Melhuish and technologists at the University of the West of England(UWE)in Bristol 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 of E. 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

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