阅读理解。
Scientists who discovered a new way of generating electricity from water say they may have come
across an alternative source of clean energy to rival wind and solar power.
The breakthrough, which scientists say is the first new way to generate electricity in 160 years, could
lead to batteries that use water instead of poisonous substances.
The scientists made the discovery when they were investigating what happens when tap water is
forced through extremely narrow glass tubes. Water squeezed down the tubes, each of which was
narrower than a tenth the thickness of a human hair, generating a small electric current that ran the length
of the tube. To produce a larger electric current, the team tried forcing water through a glass water filte
r(滤水器) that contained thousands of narrow channels lined up side by side. "When we took a syringe (注射器) of water and squeezed it through the filter, we got enough power to light a light bulb," said
Larry Kostiuk of the University of Alberta in Canada. "The harder you push the syringe, the more electric
current you get."
The current is produced because of an effect in the glass tubes. When they are filled with water,
positively charged ions (阳离子) fixed in the tubes are washed away, leaving a slight negative charge on
the glass surface. When water is then forced along the tube, the surface repels negatively charged ions in
the water while positively charged ions are attracted down the tube. The result is a net flow of positively
charged ions that sets up an electric current.
According to Dr Kostiuk, no one has ever thought to use water to produce electricity in this way.
"The last time someone came up with a way of generating electricity was Michael Faraday in 1839," he
said. "So this is the first new way of generating electricity in 160 years, which is why we are so excited
about it."
Dr Kostiuk says water batteries might one day be used to power mobile phones and calculators, but
admitted that the engineering challenges might make other applications more realistic. "You'd need to be
sure it wouldn't leak, and you'd need to make sure it wouldn't freeze," he said.
More likely would be to install the electricity-generating devices where water is already being pumped, such as at city water filtration sites, he said. "It could compete with wind and solar power," he added.
1. What does the passage mainly want to tell us about?
A. A kind of solar power discovered by scientists.
B. A kind of new energy source found in tap water.
C. The breakthrough to generate electricity 160 yeas ago.
D. A kind of new battery invented without poisonous substances.
2. The underlined word "repels" in Paragraph 4 is closest in meaning to _________.
A. rejects
B. identifies
C. attracts
D. rebels
3. Why were the scientists extremely happy about their new discovery?
A. They were the first to find a new way to produce electricity.
B. They could make an electric current to light a light bulb.
C. Their discovery could be used to invent water batteries.
D. Their discovery was made 160 years earlier than Faraday's.
4. What can we infer about potential water batteries?
A. They must be used to power mobile phones and calculators.
B. They have some possible disadvantages like water leaking.
C. They would be needed greatly at city water filtration sites.
D. They would be better than wind and solar power.