Australians have evidently realized the fact that water means life and we need to he more thoughtful in our use of this rather precious resource．Since the year 2000, Australians have managed to reduce their use of water by 14% ． In the most populous city, Sydney, they've managed to use less water in 2007 than in 1974, even though the city grew by l． 2 million souls in this period．

　　 Across the country nearly 20% of all households have water tanks．That would probably be due, in large part, to the various state governments offering generous rebates． In NSW, for example, where 24,000 households have taken up the offer, you can get $1,500 AUD back if you fix a 7,000 + litre tank and have it attached into your toilet and washing machine．

　　 Creywater use has taken off too． The Australian Bureau of Statistics suggest that it's now the second most common source of water in Australia, with over half of the country's homes reusing water from their washing machines, showers and baths． The state of Victoria leads with 70% using greywater, and Queensland, coming close behind with 63%．

　 Up in the northern state of．Queensland, some of their dams have been below 20%． Sydney's main dam is only at 56% of its potential capacity．

　 The country's ongoing drought（干旱） has seen more than 95% of the length of the Murray- Darling Basin （ the two major river systems that supply the nation's 'food basket' ） regarded as ' degraded', Supply of water has become such an issue that hydro-electric power（水力发电） output has dropped 7% in a recent 9 year period for the states of NSW, Victoria and Tasmania．Not good for promoting our uptake understanding of renewable energy in these climate changing times．But at least the message is getting through about making every drop count．

72．The underlined word "rebate" in paragraph 2 probably means　　　　　　 ．

A． discount or allowance　　　　　 　　　　　 B． water tanks for free

C． agreements or payment　　　　　 　　　　 D． washing machine of high quality

73． Which of the following statements is TRUE?

　 A． The state of Victoria is playing a leading role in greywater use．

　 B． More water has been used in Australia with the growing population．

　 C． The state of Queensland gets its water mostly from the north of its state．

　 D． Some of the dams in Queensland are too weak to hold potential water．

74． We can learn from the last paragraph that　　　　　 ．

A． the country's water shortage is partly due to continuous drought

B． large quantities of water are being used to produce electricity

C． the author hopes water resource could be used to the fullest

D． the author disagrees with the use of renewable energy

75． The passage is likely to appear in　　　　 ．

　 A． a scientist's diary B． a history paper

C． a travel guidebook　　　　　　　　　　　　　　　　　　 D． a newspaper

Scientists from South Korea are trying to convert（转化）sound waves into electricity. The research could lead to charging a cell phone from a conversation or providing energy to the nation’s electricity system generated（产生）by the noise during rash-hour traffic.

“Just as speakers transform electrical signals into sound, the opposite process —turning sound into a source of electrical power — is possible,” said Young Jun Park and Sang-Woo Kim, the joint authors of a new article in the journal Advanced Materials.

Harvesting energy from phone calls and passing cars is based on materials known as piezoelectrics. When bent, piezoelectric materials turn that mechanical energy into electricity. Lots of materials are piezoelectric: cane sugar, quartz （石英）and even dried bone which could create an electrical charge when stressed. For decades, scientists have pumped electricity into piezoelectric materials for use in environmental sensors, speakers and other devices.

Over the past few years, however, scientists have made dramatic advances in getting electricity out of piezoelectric devices. In an experiment, by using sound waves, which at 100 decibels（分贝）were not quite as loud as a rock concert （a normal conversation is about 60-70 decibels）, the South Korean scientists produced a mild electrical current of about 50 millivolts（毫伏）. The average cell phone requires a few volts to function, several times the power this technology can currently produce.

“But the real question is whether there is enough surrounding noise to act as a power source as for a cell phone,” said McAlpine, a leading scientist. A consumer probably wouldn’t want to attend a rock concert or stand next to a passing train to charge his cell phone. The South Korean scientists agree but they expect to get a higher power output as they continue their work.

1.According to the two South Korean scientists, ________.

A．sound waves can travel faster than electricity

B．new materials can send cell phone signals better

C．using cell phones adds to heavy traffic in rush hour

D．electricity and sound can be transformed into each other

2.We know from the passage that piezoelectric materials ________.

A．can produce electricity when stressed

B．are good at changing electricity into sound

C．can reduce the noise of passing cars

D．have been widely used in phones and cars

3.It can be inferred from the South Korean scientists’ experiment that ________.

A．it is hard to change sound into electricity under current conditions

B．it is impossible to make use of loud sound

C．the technology has a long way to go to have a practical use

D．the technology can power cell phones easily

4.What McAlpine doubts about the technology is ________.

A．the noise pollution                      B．the sound resource

C．the cost of piezoelectrics                 D．the safety of devices

 

Everyday rubbish could provide a valuable source of energy thanks to a clever new invention. Smelly methane（沼气）gas expelled from landfill sites containing tones of rotting household waste could be used to produce a valuable energy resource. In Europe alone land fill tips produce 94 billion cubic meters of methane per year but currently only one percent of what could be a valuable source of energy is used, the rest is burnt off to prevent an explosive build up of gas.

Methane gas forms when organic matter breaks down and is drawn off from large rubbish tips by pipes sunk into the middle of the waste. Until now this process wasn’t possible on small sites because the pipe allowed oxygen to seep in and that stop the breakdown process.

Viktor Popov of the Wessex Institute of Technology has now developed a system to modify existing landfill sites by making them airtight while the methane is extracted from sunken wells. The site is covered by a special three-layered skin whose two outer layers are made of clay with a pressurized（加压的）layer of carbon dioxide gas in the middle. As the methane is sucked out through a central well it is replaced by carbon dioxide from the middle layer rather than oxygen, allowing the breakdown process to continue.

Unfortunately there are no plans to use the power of methane even though Popov claims his invention could provide a valuable source of energy over the next 20 years.

The passage mainly introduces ______ to us.

A．how to make methane     B．a new way to make use of rubbish 

C．the valuable things in rubbish  D．the amount of rubbish beig reused

From the passage we can see that _____.

A．in Europe 94 billion cubic meters of methane is produced every year

B．some of the waste will explode if it is not burnt off

C．99% of the rubbish has been burnt off in Europe

D．only a very small part of this kind of energy is used in Europe

In the passage the underlined word “that” refers to ______.

A．methane gas     B．the long pipe    C．oxygen     D．the rubbish

Which of the following statement is NOT true according to the passage?

A．Oxygen can cause the breakdown process to stop.

B．When the methane is sucked out, oxygen will enter from the middle layer.

C．Carbon dioxide doesn’t affect the breakdown process.

D．The new invention has not been put into use.