2 . 假设你是高中生李华, 有感于校园中存在的随意涂写（to scribble）和乱丢垃圾（to litter）的行为, 请用英语给校长写一封100个词左右的信。信中应包括以下内容：
1.说明写信目的；
2.对这些行为进行批评；
3.提出建议。
注意：信的抬头、落款及信的第一句已给出（不计词数）。
June 8, 2011
Dear Mr. Headmaster,
__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Yours faithfully,

Li Hua

3 . The permafrost (永久冻土) is melting fast... that’s bad news, because these frozen soils store billions of tons of carbon dioxide, just waiting to be released. So is there a way to save the permafrost? One team of researchers thinks it may have found a possible solution: big animals and herbivores (食草动物).

Back 1996, researchers started an experiment called Pleistocene Park. They fenced about eight square miles of land in northeast Siberia. And then they introduced different types herbivores: horses, sheep and other large creatures. Since then, scientists have studied these animals effects on the ecosystem. One outcome is that these large herbivores help keep the ground very cold-cooler than it would otherwise be.

“The snow in winter is important to soil temperature, because it acts as an insulating layer (隔绝层). So the air in winter, at the high altitudes, is much colder than the soil,” Philipp Porada, ecologist at the University of Hamburg said. So the idea of this experiment was to introduce large herbivores to quantify their effects on soil temperature and see if they can actually protect permafrost soils against melting. And this works because the animals’ trampling (踩踏) leads to less insulation of the soil against cold air temperatures and results in a cooling effect.

Porada and his colleagues realized the significance of this effect, so they pulled data from Pleistocene Park to model what effect herbivores could have on permafrost if they lived in large numbers in the Arctic.

Porada said, “These herbivores in the model reduce soil temperature greatly, by 1.7 grees on average. And this leads a preservation of around 80 percent of today s permafrost area. And without the herbivore effect in the model, we found that only 50 percent of the permafrost area would remain by the year 2100.”

1. What will the permafrost’s melting result in?

A．The decrease air.	B．The cooling effect.
C．The rise the surrounding temperature.	D．The increase in herbivores.

2. Why can the herbivores help keep the ground cooler ?

A．They can make more insulating layers.

B．They can protect the snow on the ground.

C．They make the ground release lots of carbon.

D．They make cold air reach the soil more easily.

3. How did Porada feel about the finding of the experiment ?

A．It remains to be checked.	B．It’s unreasonable.
C．It’s significant.	D．It has been used widely.

4. What did Porada intend to tell us in the last paragraph ?

A．The herbivores could lead to the preservation of permafrost.

B．The herbivores would help find more permafrost areas.

C．The temperature would increase greatly in the future.

D．Only half of the permafrost would remain by the year 2100.

4 . As heat waves continue to ravage the planet, air conditioners are becoming more and more common. However, these "active" cooling devices are posing problems because the electricity consumption which most people are concerned about and the release of ozone-damaging chemicals worsen the greenhouse gas effect, resulting in the creation of heat islands and further thermal pollution. Therefore, "passive" cooling, which doesn't have such effects, has attracted considerable attention from both scientists and ordinary people in recent years.

In a recent study, a team of researchers from China and US presented an eco-friendly, low-cost smart coating to keep buildings cooler while consuming zero electricity. Infrared radiation-based passive cooling has been investigated since 2014, but challenges, mainly the expensive and unsustainable design, have greatly limited their large-scale and widespread application. Besides, the imbalance in cooling ability of these coatings during the day and night tends to lead to great day-night temperature differences as more heat is lost than gained at night.

The solution therefore requires a "smart" mechanism that can both enhance daytime cooling and minimize nighttime heat loss. To do this, the researchers created a new smart coating comprised of conventional building materials, including titanium dioxide nanoparticles, fluorescent microparticles, and glass microspheres that were engineered to reflect most of the sunlight. Specifically, the titanium dioxide particles effectively reflect sunlight through light scattering（撒播）while the fluorescent particles increase the amount of reflection by changing the absorbed sunlight into fluorescence emissions, which drive more heat away from the building. Meanwhile, the glass microspheres re-send mid-infrared broadband radiation, allowing not only heat loss, but allowing heat exchange to take place between the building and the sky.

The coating was tested on a model concrete building. Through this efficient heat exchange with the sky, daytime cooling was strengthened while nighttime cooling was reduced. The building's inside temperature was always maintained at around 26℃, even when the out-side temperature varied from 24℃ to 37℃ during the day. We believe this new coating will make it to commercialization soon, enabling a sustainable, passive cooling technology that could help to fight climate change and the global energy crisis.

1. What is the virtue of passive cooling?

A．It is simple to design.	B．It uses no chemicals.
C．It is smart.	D．It uses no power.

2. Why couldn't the former coating be applied commercially?

A．It was hard to design.

B．Its material was hard to produce.

C．Its heat loss and cooling are imbalanced.

D．It wasn't tested on a model concrete building.

3. Which of the following can replace the underlined word "mechanism" in paragraph 3?

A．Metal.

B．System.

C．Platform.

D．Building.

4. What is the text mainly about?

A．The principle of air-conditioning.

B．The differences between active and passive cooling.

C．A new coating to keep buildings cool without electricity.

D．A new building to maintain its inside temperature without electricity.

5 . Scientist， conservation organizations and government trying to stop the trend of extinction （灭绝） often focus on protected areas such as national parks and wildlife preserves. But with as many as million species（物种） at risk， this plan of action may not be enough to conserve wildlife.

Slowing the mass extinction that now appears to be underway will require more creative means of coexisting alongside wild plants and animals. A new study indicates the effectiveness of some such approaches by examining some lands managed by indigenous groups.

“ We show really strongly that， from a biodiversity standpoint in terms of species richness，indigenous － managed lands are at least comparable to protected areas， ” says biologist Richard Schuster of Carleton University. And in some places， they are better than parks and preserves －even though indigenous communities may use their lands’ resources by hunting or searching for food.

Schuster and his team analyzed more than 15，000 areas in Australia， Brazil and Canada. They found that the total diversity of wildlife was highest on lands either managed or co － managed by indigenous groups， while randomly selected areas with no formal protection were the least bio－diverse. For threatened species in particular， indigenous lands scored slightly higher than protected lands on overall species richness in Brazil and Canada， as well as higher for threatened animals in Australia.

Each country has a different geography， climate and history. Yet remarkably， Schuster says， the best indicator for species diversity is whether a given area was managed by an indigenous community. He pointed out that practices such as sustainable（可持续的） hunting， fishing and searching， as well as burning， are more likely to occur in such areas. Don Hankins， an ecologist at California State University，agrees. “ there’ s probably going to be more of a connection to the land， ” he says， “ and a use of the land for the things that are there， compared to a national park. ”

“ It’ s really important to listen to the people who live on the land and have them drive the stewardship efforts going forward， ” Schuster says， adding that partnering with indigenous communities may enable the world’ s countries to better meet a wide range of conservation goals： “ We really need all the help we can get as a global community to prevent species extinction that we’ re facing right now. ”

1. What does the underlined word “ indigenous” probably mean in Paragraph 2？

A．Social.	B．Native.
C．Protected.	D．Threatened.

2. What did Richard Schuster find in his study？

A．National parks are even higher in species diversity.

B．Indigenous communities overhunted on their lands.

C．Some preserves almost have no formal protection.

D．Indigenous lands do better in keeping bio－diversity.

3. Which of the following statements may Don Hankins agree with？

A．Species diversity depends on geographical positions.

B．Humans’ everyday activities are no longer sustainable.

C．Indigenous groups have a close bond with their lands.

D．Protected areas work perfectly in wildlife protection.

4. What is the text mainly about？

A．Beating back extinction.	B．Dealing with environmental problems.
C．Setting up nature reserves.	D．Fighting against unsustainable behaviors.

6 . SYDNEY —Australian scientists have designed a system which uses microwaves to break down plastic into an environmentally friendly by-product.

Head of Electrical Engineering at Australia’s James Cook University, Prof. Mohan Jacob revealed on Thursday that by using microwaves, plastic waste can be converted into biochar(生物炭), charcoal that can be used as a soil conditioner.

“We are developing a processing room, which could process many kinds of plastic materials, up to 5 kilograms of waste,” Jacob said. “It will be a typical example system for the development of biochars from different types of plastics under various conditions.” Jacob explained that microwave energy is used to heat the plastic waste above 600 degrees centigrade within the custom-made room, where it ends up as a biochar, which can then be used to improve the properties of soil.

Currently underway is step one of the project, testing the room, after which, step two will involve improving the energy efficiency of the system and maximizing the yield of by-products. If all goes to plan, step three will be to construct a medium scale waste processing system which is customizable and can be installed remotely.

Jacob said that with the average person using 130 kg of plastic every year, there is an urgent need for developing better ways of processing it.

“Perhaps contrary to popular opinion, plastic is an indispensable material in modern life. It is cheap, competent, lightweight, and has many benefits like maintaining food quality and safety and preventing waste,” he said.

However, “abandoned plastics endanger our marine wildlife, and have begun to enter the food chain. There is an urgent need for developing technologies to recover plastic waste.”

1. How does the system function?

A．Microwaves are used to produce plastic.

B．Plastic waste is heated in the microwaves.

C．Plastic waste is cut into pieces and buried into the soil.

D．Microwaves change plastic waste into biochar by heating.

2. Which statement is true according to Jacob?

A．Plastic consumption now is acceptable.

B．Plastic should be abandoned in our life.

C．The system of processing plastic has come into use.

D．Finding better ways to deal with plastic waste is urgent.

3. What does “recover” in the last paragraph mean?

A．Make up for a loss in time.

B．Find or regain lost possession.

C．Extract or recycle an energy source for reuse.

D．Return to a normal state of health, mind or strength.

4. What does the passage mainly tell about?

A．3 steps of processing plastic waste.

B．A way of producing plastic products easily.

C．A new system of breaking down plastic waste.

D．A program designed for plastic use in the daily life.