【推荐1】The San Diego County Water Authority has an unusual plan to use the city’s scenic San Vicente Reservoir (水库) to store solar power so it’s available after sunset. The project could help unlock America’s clean energy future.

Perhaps ten years from now, if all goes smoothly, large underground pipes will connect this lake to a new reservoir, a much smaller one, built in a nearby valley about 1100 feet higher. When the sun is high in the sky, California’s abundant solar power will pump water into that upper reservoir. It’s a way to store the electricity. When the sun goes down and solar power disappears, operators would open a valve (阀门) and the force of 8 million tons of water, falling back downhill through those same pipes, would drive machines capable of producing 500 megawatt s of electricity for up to eight hours. That’s enough to power 130, 000 typical homes.

“It’s a water battery!” says Neena Kuzmich, Deputy Director of Engineering for the water authority. She says energy storage facilities like these will be increasingly critical as California starts to rely more on energy from wind and solar, which produce electricity on their own schedules, without considering the demands of consumers. Californians learned this during a heat wave this past summer. “Everybody in the state of California got a text message at 5:30 in the evening to turn off their appliances,” Kuzmich says. The sun was going down, solar generation was disappearing, and the remaining power plants, many of them burning gas, couldn't keep up with demand. The reminder worked: people stopped using so much power, and the grid (电网) survived.

Yet earlier on that same day, there was so much solar power available that the grid couldn’t take it all. Grid operators turned away more than 2000 megawatt hours of electricity that solar generators could have delivered, enough to power a small city. That electricity was wasted. There was no way to store it for later, when operators desperately needed it.

1. What is the function of Paragraph 2?

A．To present the importance of a reservoir.	B．To introduce the usage of solar energy.
C．To recall a situation in recent ten years.	D．To explain a way to store electricity.

2. What does the underlined word “critical” in Paragraph 3 probably mean?

A．Negative.

B．Affordable.

C．Flexible.

D．Significant.

3. Why was a text message sent to everyone in California?

A．To remind people of lack of energy.	B．To warn people of danger.
C．To tell people the sunset time.	D．To persuade people into burning gas.

4. Which of the following is a suitable title for the text?

A．Scenic San Vicente Reservoir	B．Water Batteries to Store Solar Power
C．San Diego County Energy Crisis	D．Machines to Store Water in California

【推荐3】Could looking through trees be the view to a greener future? Trees replacing the clear glass in your windows is not a work of science fiction. It’s happening now.

Forest Products Laboratory researcher Junyong Zhu together with colleagues from the University of Maryland and University of Colorado has developed a transparent wood material that may be the window of tomorrow. Researchers found that transparent wood has the potential to outperform glass currently used in construction in nearly every way.

While glass is the most common material used in window construction, it comes with quite a few bad consequences. Heat easily transfers through glass and amounts to higher energy bills when it escapes during cold weather and pours in when it’s warm. Glass production used for construction also comes with a heavy carbon footprint. Manufacturing emissions alone are approximately 25,000 metric tons per year, without considering the heavy footprint of transporting the glass.

The innovation was developed using wood from the balsa tree, which is native to South and Central America. The team treated balsa wood to an oxidizing bath, where the wood is kept in a bleach solution at room temperature to remove the light-absorbing substance from the structure. The wood is then penetrated (注入) with a synthetic polymer called polyvinyl alcohol (PVA), creating a product that is virtually transparent. So the transparent wood is created, which is far more durable and lighter than glass.

Switching to transparent wood could prove to be cost efficient as well. It is approximately five times more thermally efficient than glass, cutting energy costs. It is made from a sustainable, renewable resource with low carbon emissions.

With all of these potential benefits for consumers, manufacturing and the environment, the case for transparent wood couldn’t be clearer.

1. What is the main problem with glass used in window construction?

A．It is inefficient in letting heat out.

B．It is inconvenient to transport.

C．It causes a high ecological price.

D．It scarcely reflects light and heat.

2. What does the underlined part “a bleach solution” refer to?

A．A way to make colors fade.

B．A liquid to make objects pale.

C．A container to store liquids.

D．A process to solve problems.

3. What is the author’s attitude toward transparent, wood?

A．Skeptical.

B．Ambiguous.

C．Appreciative.

D．Conservative.

4. What do the researchers probably agree with?

A．Innovation is the vitality of scientific housing.

B．Things are not always what they seem.

C．There are more ways to the wood than one.

D．There is nothing permanent except change.

【推荐2】What is the single most effective way to reduce greenhouse-gas emissions? Go vegetarian? Replant the Amazon? Cycle to work? None of the above. The answer is: make air-conditioners radically better. On one calculation, replacing refrigerants(制冷剂) that damage the atmosphere would reduce total greenhouse gases by the equivalent of 90bn tonnes of CO2 by 2050. Making the units more energy-efficient could double that.

Air-conditioning is one of the world’s great overlooked industries. Automobiles and air-conditioners were invented at roughly the same time, and both have had a huge impact on where people live and work. Unlike cars, though, air-conditioners have drawn little criticism for their social impact, emissions or energy efficiency. Most hot countries do not have rules to govern their energy use.

Yet air-conditioning has done quite a lot things to benefit humankind. It has transformed productivity in the tropics and helped turn southern China into the workshop of the world. In Europe, its spread has pushed down heat-related deaths ten times less than what it was in 2003, when 70,000 people, most of them elderly, died in a heatwave. For children, air-conditioned classrooms and dormitories are associated with better grades at school.

Environmentalists who call air-conditioning “a luxury we cannot afford” have half a point, however. In the next ten years, as many air-conditioners will be installed around the world as were put in between 1902 (when air-conditioning was invented) and 2005. Until energy can be produced without carbon emissions, these extra machines will warm the world. At the moment, therefore, air-conditioners create a vicious cycle. The more the earth warms, the more people need them. But the more there are, the warmer the world will be.

Cutting the impact of cooling requires three things (beyond turning up the thermostat(温度调节器) to make rooms less Arctic). First, air-conditioners must become much more efficient. The most energy-efficient models on the market today consume only about one-third as much electricity as average ones. Minimum energy-performance standards need to be raised, or introduced in countries that lack them altogether, to push the average unit’s performance closer to the standard of the best.

Next, manufacturers should stop using damaging refrigerants. One category of these, hydrofluorocarbons, is over 1,000 times worse than carbon dioxide when it comes to trapping heat in the atmosphere. An international deal to phase out these pollutants, called the Kigali amendment, will come into force in 2019. Foot-draggers should approve and implement it; America is one country that has not done so.

Last, more could be done to design offices, malls and even cities so they do not need as many air-conditioners in the first place. More buildings should be built with overhanging roofs or balconies for shade, or with natural air-circulation. Simply painting roofs white can help keep temperatures down.

Better machines are necessary. But cooling as an overall system needs to be improved if air-conditioning is to fulfil its promise to make people healthier, wealthier and wiser, without too high an environmental cost. Providing indoor sanctuaries of air-conditioned comfort need not come at the expense of an overheating world.

1. Why does the author think air-conditioning is an overlooked industry？

A．Because many hot countries haven’t put the energy-controlling rules into force.

B．Because it has caused the same impact on people’s life and work as automobiles have.

C．Because it has brought great economic, physical, and educational benefits to humans.

D．Because it doesn’t get the due criticism for its environmental impact as automobiles do.

2. What can we learn from Paragraph 4?

A．The price of air-conditioning will go up due to the large demand for it.

B．A high environmental cost will come along with the air-conditioning service.

C．Environmentalists are expecting extra machines which can warm the world.

D．Governments partially agree that air-conditioning is a luxury we cannot afford.

3. With regard to the measures to cut the impact of cooling, which of the following statements is TRUE?

A．Manufacturers should only stop using hydrofluorocarbons.

B．People should avoid turning up the air-conditioners to have cool rooms on hot days.

C．People should adopt more environmentally-friendly materials when designing buildings.

D．Governments should give a green light to the agreement on eliminating the pollutants.

4. The author writes this passage to _______.

A．arouse people’s attention to the global warming.

B．appeal for the global joint efforts to combat global warming.

C．give credit to air-conditioning for its great contributions to humans

D．offer a new perspective on how to reduce greenhouse gasses emissions