2 . The warm coast of California is a place where many western monarch butterflies(帝王蝶) stay during the cold winter months in the United States. Researchers fear the record low number of monarchs this year could mean the insects are in danger of disappearing in the near future.

Researchers from the Xerces Society said they found fewer than 2,000 orange-and-black butterflies in the yearly count this January. That number showed a big drop from the tens of thousands in recent years. In the 1980s, there were millions of them in trees from Northern California's Marin County to San Diego County near the Mexico border. Last winter, it recorded around 29,000 butterflies in its yearly survey. That was similar to the winter before,when an all-time low of 27,000 monarchs was counted.

Every winter, western monarch butterflies fly south from the northwestern U. S. to California. At the start of November, they arrive in California, often going to the same places and even the same trees. Once warmer weather arrives in March, the monarchs begin their journey back north, stopping somewhere along the route to lay eggs. After egg-laying, the adult butterflies die and the northward migration(迁徙)is continued by their new generations. Thus the monarch butterflies disperse across the country.

Scientists say there are several causes for the extremely low numbers of butterflies in the western states. Homebuilding and chemical use have destroyed milkweed (马利筋) plants along their migratory path. The plants are needed for monarch butterflies to grow and develop, which is the only food monarchs will eat and the only place they will lay their eggs on. Climate change influences the growth of                    wild plants. And huge wildfires in the west may also have influenced their migration.

Luckily, some public campaigns have encouraged people to plant milkweed in their yards and cities. People can also help scientists collect data, which is critical for developing conservation policies to protect monarchs. Then there are many larger—scale efforts to protect habitats and better manage land for reproduction.

1. How does the author develop paragraph 2?

A．By listing figures.	B．By making classifications.
C．By explaining definitions.	D．By analyzing cause and effect.

2. What does the underlined word "disperse" in paragraph 3 probably mean?

A．Spread.

B．Gather.

C．Disappear.

D．Hide.

3. Which word best describes monarch butterflies' relationship with milkweed?

A．Independent.

B．Inseparable.

C．Unstable.

D．Unfriendly.

4. What's the main idea of the last paragraph?

A．Monarch butterflies' life habits.

B．Monarch butterflies' living habitats.

C．Threats to monarch butterflies' survival.

D．Efforts to preserve monarch butterflies.

5 . Plastic—Eating Worm

Humans produce more than 300 million tons of plastic every year. Almost half of that ends up in landfills(垃圾填埋场) , and up to 12 million tons pollute the oceans. So far there is no effective way to get rid of it, but a new study suggests an answer may lie in the stomachs of some hungry worms(幼虫).   

Researchers in Spain and England found that the worms of the greater wax moth(大蜡螟) can break down polyethylene(聚乙烯), which accounts for 40% of plastics.

That is to say, part of plastics can be consumed by this kind of worms. The team left 100 wax worms on a plastic shopping bag for 12 hours, and the worms consumed and broke down about 92 milligrams, or almost 3% of it. To confirm that the worms' chewing alone was not responsible for the polyethylene breakdown, the researchers made some worms into paste(糊状物)and applied it to plastic films. 14 hours later the films had lost 13% of their mass—apparently broken down by enzymes(酶)from the worms' stomachs. Their findings were published in Current Biology.

Federica Bertocchini, co—author of the study, says the worms' ability to break down their everyday food—beeswax—also allows them to break down plastic." Wax is a complex mixture, but the basic bond in polyethylene, the carbon—carbon bond, is there as well," she explains. "The wax worm developed a method or system to break this bond."

Jennifer Debruyn, a microbiologist at the University of Tennessee, who was not involved in the study, says it is not surprising that such worms can break down polyethylene. But compared with previous studies, she finds the speed of breaking down in this one exciting. The next step, DeBruyn says, will be to identify where the enzyme comes from. Is it an enzyme produced by the worm itself or by its gut microbes(肠道微生物)?

Bertocchini agrees and hopes her team's findings might one day help make use of the enzyme to break down plastics in landfills. But she expects using the chemical in some kind of industrial process—not simply "millions of worms thrown on top of the plastic."

1. What can we learn about the worms in the study?

A．They take plastics as their everyday food.

B．They can consume plastics.

C．They end up in landfills.

D．They are new creatures.

2. According to Jennifer DeBruyn, the next step of the study is to ________.

A．prove the research findings

B．discover other kinds of worms

C．increase the breakdown speed

D．find out the source of the enzyme

3. It can be inferred from the last paragraph that the chemical might ________.

A．help to raise worms

B．help make plastic bags

C．be used to clean the oceans

D．be produced in factories in future

4. What is the main purpose of the passage?

A．To propose new means to keep eco—balance.

B．To present a way to break down plastics.

C．To introduce the diet of a special worm.

D．To explain a study method on worms.

8 . What is the best part of a typical relaxing summer day? Nothing is better than sitting in an armchair with a beer and some chips in your hand, enjoying the great comfort.

The much-loved combination of beer and chips is being exploited for the first time to deal with climate change. Chips firm Walkers has adopted a technique it says will cut CO₂ emissions (排放) from its production process by 70%.

The technology will use CO₂ captured from beer processing in a brewery (啤酒厂), which is then mixed with potato waste and turned into fertilizer. It will then be spread on UK fields to feed the following year’s potato crop. Creating fertilizer normally produces high CO₂ emissions, but the technology adopted by Walkers makes fertilizer without generating CO₂. So, the beer-and-chips combination performs a double function. It stops the emission of brewery CO₂ into the atmosphere — and it saves on the CO₂ normally generated by fertilizer production.

This Creative win-win solution was developed with an approval from the UK government by a 14-employee start-up called CCm. The fertilizer was experimented on potato seed beds this year, and next year Walkers will install CCm equipment at its Leicester factory to prepare for its 2022 crop.

A decision has not yet been made on which brewery Walkers will work with on this. The new technology adds to carbon-saving techniques already under way. The firm has installed an anaerobic digester (厌氧消化池), which feeds potato waste to bacteria to produce a useful gas. The gas is burned to make electricity for the chip-frying process — so this saves on burning gas or coal.

The new system will go a step further by taking away potato “cake” left after digestion — and mixing the brewery CO₂ into it to make an enriched fertilizer which will help put carbon back into the soil as well as encouraging plant growth.

It’s an example of scientists finding ways to use CO₂ emissions which otherwise would increase the over-heating of the planet.

1. What is the purpose of the first paragraph?

A．To draw readers’ attention.

B．To entertain readers.

C．To show how useful beer and chips are to our life.

D．To introduce a way of life.

2. Which of the following is an advantage of the system?

A．It will be totally cost-free.

B．It doesn’t consume any energy.

C．It will be a perfect solution to climate change.

D．It is environmentally-friendly.

3. What is Paragraph 3 mainly about?

A．How CO2 is turned into fertilizer.

B．How the technology stops CO2 emissions.

C．How an energy-saving green technology works.

D．The advantages of a new technology.

4. What can be inferred from the text?

A．The technology will fix the problem of global warming.

B．Walkers has a wide range of partner choices.?

C．This technology will be adopted by many chips firms soon.

D．Scientists are seeking solutions to climate change.

9 . The carbon footprint shows how much carbon dioxide a person emits(排放)in everyday life. It measures the amount offossil(化石)fuels and electricity someone uses up as well as the carbon footprint of the products they buy. When we use our cars or heat our homes with carbon dioxide，various other gases are set free.     1    

You can measure your carbon footprint by using a calculator that you can find on various websites.     2     In America for example，every citizen produces about 28 tons of carbon dioxide and other dangerous gases a year；in Great Britain the amount is about 10 tons.

    3     The way we travel，for example，has a major effect on our environment. Use your bike or walk for short distances. Public transport is a way of getting to places without putting a burden on the environment.     4     Many environmental experts，however，argue that it often saves energy to buy food that is produced naturally in faraway places than consuming food grown locally in greenhouses. In your home you can contribute to saving energy by turning off lights if you don’t need them or by avoiding the use of air conditioners. Recycling plastic glass and paper can also reduce your carbon footprint dramatically.

    5     Only if we concentrate on reducing carbon emissions together can we hope to make our environment better.

A．Many people travel between cities and suburbs every day.

B．The carbon footprint is usually measured in tons of CO2 per year.

C．These emissions lead to a thicker atmosphere and global warming.

D．It is also vital to persuade others to take the same steps that you do.

E．There are many actions you can take to reduce your carbon footprint.

F．The websites also provide carbon storage tools and methods for individuals.

G．Buying local food is another way of restricting emission into the atmosphere.

10 . Greenland is the biggest island in the world. And the ice sheet that sits atop it is massive. “The pile of ice being so thick, it extends more than 10, 000 feet above the ocean. And if all that ice were to melt and go into the ocean, global sea levels would rise by 24 feet everywhere around the world,” said Jason Briner, a geologist at the University at Buffalo. The ice sheet is melting, of course. But just how much, compared to the past?

Briner’s team did a computer simulation（模拟)of the southwest of the Greenland ice sheet, which he says is a good proxy for ice melt across the entire ice sheet. The researchers plugged past climate data into that model to “hindcast”, rather than forecast, the past activity of the ice sheet. They then checked the model’s predictions of the past shape and size of                    the ice sheet by looking at piles of rocks and dirt on Greenland today, which outline the edges of ancient ice. And the simulation was in good agreement with the actual situation.

Using that reconstruction of the ice sheet over time, the team could compare the ice sheet’s historic losses to those happening today under human-caused global warming. And they determined that Greenland is on track to lose more ice this century than during any century in the past 12, 000 years — possibly four times as much. The results appear in the journal Nature.

Ultimately it’s up to us how much ice actually melts. “Humanity has the button — the carbon button — and that button is going to influence the rates of ice loss from the Greenland ice sheet.” If the world goes net carbon zero by 2100, for example, Briner says ice loss could stop, entirely at the end of the century, according to one model. “That was what kept me from being completely depressed about our study. ” Dozens of countries have already announced goals to go net carbon zero by the middle of this century — so far the U. S. is not one of them.

1. What does the underlined word “proxy” in Paragraph 2 refer to?

A．Combination.	B．Example.
C．Recommendation.	D．Interpretation.

2. What do we learn from the computer simulation done by Briner’s team?

A．It is conducted by predicting the activity of the ice sheet.

B．It centers on ice melt throughout the entire ice sheet.

C．It shows the ice sheet’s losses are in decline.

D．It consists with the ice sheet’s actual circumstance.

3. Which of the following can be the best title for the passage?

A．Greenland Is Melting Faster

B．Global Sea Levels Are Rising

C．America Causes the Ice Sheet to Melt

D．Man Can Conquer Nature