1 . The oceans play a crucial role in lightening global warming by absorbing carbon dioxide emissions. However, in a study conducted by the University of Texas, researchers found that the oceans’ capacity to absorb carbon dioxide (CO₂) would reach its maximum by 2100 and decrease to half of its current efficiency by 2300, based on a climate simulation (模拟) that was set for a worst-case emissions scenario (设想).
The decline happens because of a surface layer of low-alkalinity (碱度) water that can hinder the ability of the oceans to absorb CO₂. Alkalinity affects how much CO₂ can dissolve in seawater. Although the emissions scenario used in the study is unlikely because of global efforts to limit greenhouse gas emissions, the findings reveal a previously unknown tipping point that if activated would release an important brake on global warming.
“We need to think about these worst-case scenarios to understand how our CO₂ emissions might affect the oceans not just this century, but next century and the following centuries. Climate simulations had previously shown that the oceans slow their absorption of CO₂ over time, but none had considered alkalinity as an explanation. We recalculated pieces of a 450-year simulation until we hit on alkalinity as a key cause of the slowing.” said Megumi Chikamoto, who led the research at the University of Texas Institute.
The effect begins with extreme climate change, which slows ocean currents. This leaves the surface of the oceans covered in a warm layer of fresh water that won’t mix easily with the cooler, more al kaline waters below it. That means more of it is left behind in the atmosphere. This in turn produces faster warming, which sustains and strengthens the low-alkalinity surface layer. Co-author, Pedro DiNezio, said that the discovery was a powerful reminder that the world needs to reduce its CO₂ emissions to avoid crossing this and other tipping points.
1. What may happen after the year 2300?| A．More CO₂ will be absorbed by the oceans. |
| B．The oceans will lose all their current efficiency. |
| C．The world will face even more severe warming. |
| D．The oceans will be less crucial to global warming. |
| A．Improve. | B．Weaken. | C．Protect. | D．Control. |
| A．Finding why they slow CO₂ intake is hard. |
| B．Their ability to absorb CO₂ is at their maximum. |
| C．They will decide on the future of human beings. |
| D．They will slow down CO₂ absorption very quickly. |
| A．A biology textbook. | B．A government report. |
| C．Science fiction. | D．An environmental journal. |
2 . A shocking 53.6 million metric tons of electronic waste was discarded last year, a new UN-backed report has revealed. The report shows that e-waste is up by 21% from five years ago. This isn’t surprising, considering how many more people are adopting new technology and updating devices regularly to have the latest versions, but the report also shows that national collection and recycling strategies are nowhere close to matching consumption rates.
E-waste contains materials including copper (铜), iron, gold and silver, which the report gives a conservative value of $ 57 billion. But most are thrown away or burned rather than being collected for recycling. Precious metals in waste are estimated to be worth $ 14 billion, but only $ 4 billion-worth is recovered at the moment.
While the number of countries with national e-waste policies has grown from 61 to 78 since 2014, there is little encouragement to obey and a mere 17% of collected items are recycled. If recycling does occur, it’s often under dangerous conditions, such as burning circuit boards to recover copper, which “releases highly poisonous metals” and harms the health of workers.
The report found that Asia has the highest amounts of waste overall, producing 24.9 million metric tons (MMT), followed by Europe at 12 MMT, Africa at 2.9 MMT, and Oceania at 0.7 MMT.
But whose responsibility is it? Are governments in charge of setting up collection and recycling points, or should companies be responsible for recycling the goods they produce? It goes both ways. Companies do need to be held accountable by government regulations and have incentives to design products that are easily repaired. At the same time, governments need to make it easy for citizens to access collection points and deal with their broken electronics in a convenient way. Otherwise, they may turn to the easiest option — the landfill.
1. What does the underlined word “discarded” most probably mean?| A．increased | B．distributed | C．thrown away | D．consumed |
| A．The functions of policies. | B．The great damage to environment. |
| C．The change of consumption rates. | D．The urgency of recovering e-waste. |
| A．It does harm to the workers’ health. | B．It lacks national policy support. |
| C．It hardly makes profits. | D．It takes too much time. |
| A．New technology should be used to update old devices. |
| B．Governments and companies should take responsibilities. |
| C．Non-poisonous metals had better be used in e-device. |
| D．Citizens must play a key role in recycling e-waste. |
3 . Eating too much fatty food, exercising too little and smoking can raise your future risk of heart disease. But there is another factor that can cause your heart problems more immediately: the air you breathe.
Previous studies have linked high exposure (暴露) to environmental pollution to an increased risk of heart problems, but two analyses now show that poor air quality can lead to heart attack or stroke (中风) within as little as a few hours after exposure. In one review of :he research, scientists found that people exposed to high levels of pollutants (污染物) were up to 5% more likely to suffer a heart attack within days of exposure than those with lower exposure. A separate study of stroke patients showed that even air that the U. S. Environmental Protection Agency(EPA) considers to be of “moderate” (良好) quality and relatively safe for our health can raise the risk of stroke as much as 34% within 12 to 14 hours of exposure.
The authors of both studies stress that these risks are relatively (相对地) small for healthy people and certainly modest compared with other risk factors such as smoking and high blood pressure However, it is important to be aware of these dangers because everyone is exposed to air pollution regardless of lifestyle choices. So stricter regulations by the EPA of pollutants may not only improve environmental air quality but could also become necessary to protect public health.
1. The text mainly discusses the relationship between ________.| A．heart problems and exercising |
| B．heart problems and smoking |
| C．heart problems and fatty food |
| D．heart problems and air quality |
| A．Relatively high. | B．Relatively low. | C．Too low. | D．Too high. |
| A．Stricter regulations on pollutants should be made. |
| B．Eating fatty food has immediate effects on your heart. |
| C．The EPA did many studies on air quality. |
| D．Moderate air quality is more harmful than smoking. |
| A．introduce | B．describe | C．entertain | D．persuade |
1. Where did the speaker move things from the yard?
| A．Into the garage. | B．Into the basement. | C．Into the storeroom. |
| A．Some flashlights. | B．A radio. | C．Food and water. |
| A．About 80 miles an hour. |
| B．About 90 miles an hour. |
| C．About 100 miles an hour. |
| A．She listened to the news on the radio. |
| B．She looked after her husband. |
| C．She stayed in the bathroom. |
5 . A flood can develop slowly, over time or rapidly, as in the case of flash floods which can develop in just a few minutes and without signs of rain.
Create an evacuation plan in case you have to evacuate your home. Pay attention to the safe areas you can go to. Prepare food kits for natural disasters that you can easily take with you if you have to leave your house.
If there is a possibility of a flash flood, leave your home and move to higher ground at once. Do not wait for instructions to move. Evacuation may also cause a shortage in the food supply.
While evacuating, avoid walking through moving water. Even six inches of moving water can make you fall. If you have to walk in water, walk where the water is not moving.
Do not drive into flooded areas. If floodwaters rise around your car, abandon (舍弃) the car and move to higher ground, when water is not moving or not more than a few inches deep.
| A．They don’t know where to look for shelter. |
| B．You and the car can be swept away quickly. |
| C．Use a stick to check the ground in front of you. |
| D．Be aware if the area you’re at is at risk of a flood. |
| E．There is no telling when another flood may happen. |
| F．It would help to store food for emergency situations. |
| G．During these conditions, hunger becomes a very real problem. |
6 . Back in 2007, Uruguay had a serious problem with no obvious answer: The economy was growing very fast, but there wasn’t enough energy to power the rapid
Then Ramón Méndez Galain, a physicist, started
Méndez Galain’s plan was built around two simple
To solve the problem of how to pay for all those wind farms, Méndez Galain came up with a variation on a(n)
The strategy worked
| A．decline | B．growth | C．consumption | D．program |
| A．building | B．blocking | C．repairing | D．seeking |
| A．rely on | B．find out | C．refer to | D．give up |
| A．risk | B．power | C．pollution | D．benefit |
| A．facts | B．theories | C．answers | D．principles |
| A．water | B．light | C．wind | D．ice |
| A．tended | B．undeveloped | C．protected | D．limited |
| A．break | B．put | C．send | D．turn |
| A．tool | B．software | C．image | D．approach |
| A．responsible | B．weak | C．private | D．profitable |
| A．public | B．opposite | C．rich | D．powerful |
| A．managing | B．selling | C．abandoning | D．starting |
| A．hardly | B．relatively | C．unexpectedly | D．rarely |
| A．forgotten | B．achieved | C．apologized | D．approved |
| A．income | B．food | C．supply | D．electricity |
7 . Researchers have found a chemical from a kind of worm (蠕虫) can break down one of the most common forms of plastic. The finding could open up new ways to deal with pollution.
There have been several studies showing that microorganisms can release enzymes (酶) that cause the plastics to start to break down, but that process may take a long time. The recently-discovered enzymes were found in the saliva (唾液) of the waxworm. They appear to act in only a few hours.
Federica Bertocchini is one of the researchers, who is also a beekeeper and always stores honeycombs, which are built by bees to store honey. One year Bertocchini found her honeycombs full of waxworms. She cleaned the honeycombs and put the worms in a plastic bag. When she returned later, she found that the bag was full of holes. She wondered if the worms were eating the plastic, or if there was a chemical reaction that caused the holes. “We checked and found that the plastics had been broken down,” she said.
In her latest research, Bertocchini and her co-workers found two enzymes in the worm’s saliva. The enzymes appeared to break down plastics in only a few hours.
Bertocchini’s team is still trying to understand how the worms break down the plastics. They know much more research is needed before the findings can be used to process plastic waste. However, Bertocchini said the enzymes could be put into a water mixture and then put “over piles of collected plastics” in a waste center. She said that, in the future, the enzymes could be used in homes, where families could deal with their own plastic waste.
1. What can we learn about the microorganisms in para. 2?| A．They are fond of eating small pieces of plastics. |
| B．They are widely used to deal with plastic pollution. |
| C．It takes long for their enzymes to break down plastics. |
| D．They can easily produce a large amount of useful saliva in a short time. |
| A．By accident. | B．By keeping waxworms. |
| C．By doing experiments. | D．By studying bees. |
| A．The bees flew to and bit it. | B．There was a chemical reaction. |
| C．There were some sharp things in it. | D．The worms chewed and swallowed the plastic. |
| A．It’s a theoretical possibility, but it won’t happen. | B．It may replace the usual ways soon. |
| C．It is getting increasingly popular. | D．There is still a long way to go. |
8 . Now, Earth Day is celebrated every year on April 22. A man, called Senator Gaylord Nelson Take, was determined to change the way we treated our planet. He didn’t stop his work until he had made a difference.
In 1963, Senator Gaylord Nelson wasn’t happy with the earth’s condition. He wanted to clean up the planet and solve pollution and environmental problems. As a senator, Gaylord Nelson was someone chosen by US citizens to help make laws, so he had a lot of power. He went to John F. Kennedy, the President at the time, with his concerns. The President agreed that the planet’s environment was a serious issue, so President Kennedy went around the country on a fiveday tour to promote (宣传) the idea of cleaning up the planet. People began making small changes, but it wasn’t enough.
A few years later, Senator Nelson decided to put one day aside every year for the cause of saving the planet. On April 22,1970, the first Earth Day was celebrated; 20 million American demonstrators (示威者) took part in Earth Day activities. Since then, Earth Day has become an international holiday. People all over the world are doing something to make the earth a cleaner, better place. Today more than 500 million people in 164 countries participate (参与) in Earth Day festivities!
Then, what can you do to make a difference?
*Encourage your family to recycle on a regular basis. It is a good way to help the earth!
*Switch to energyefficient light bulbs in your house to reduce the effects of global warming.
*Every glass bottle you recycle saves enough energy to run a TV for an hour and a half, while recycling an aluminum (铝) bottle can save enough energy to run your TV for three hours!
*Turn out the lights when you leave a room — unless someone’s still there!
*Use reuseable containers for your school lunches and snacks.
1. What does a senator usually do according to the passage?| A．Cleaning up the planet. | B．Solving population problems. |
| C．Helping make laws. | D．Talking to the President. |
| A．in America | B．in Britain |
| C．in 164 countries | D．across the world |
| A．For a half hour. | B．For an hour. |
| C．For an hour and a half. | D．For three hours. |
| A．It was in 1963 that Senator Nelson came up with the idea of choosing a day as Earth Day. |
| B．John F. Kennedy agreed to put April 22 aside every year as Earth Day. |
| C．President Kennedy agreed with Nelson’s idea of cleaning up the planet. |
| D．More than 500 million people took part in the first Earth Day activities. |
9 . In 1620, about half the USA was covered by forests. Today the forests have almost gone. A lot of good land has gone with them, leaving only sand. China doesn’t want to copy the USA’s example. We’re planting more and more trees. We’ve built the “ Great Green Wall” of trees across northern part of our country. The Great Green Wall is 7,000 kilometres long, and between 400 and 1,700 kilometres wide. It will stop the wind from blowing the earth away. It will stop the sand from moving towards the rich farmland in the south. More “Great Green Walls” are needed. Trees must be grown all over the world. Great Green Walls will make the world better.
1. In 1620, about ________ the USA was covered by forests.| A．a third | B．half | C．two thirds | D．a fourth |
| A．sand | B．water | C．wind | D．forests |
| A．7,000 kilometers | B．1,700 kilometers |
| C．7,000 meters | D．400 kilometers |
| A．China | B．the USA |
| C．some countries | D．every part of the world |
| A．The Great Wall | B．Tall buildings |
| C．Great Green Walls | D．Flowers and grass |
10 . Going Zero Waste means more than dealing with the rubbish we create. It means reducing it, too. People who go Zero Waste are careful about what they do. They never take more than they need, they reuse plastic bags, and they make good plans not to buy more than necessary before going shopping.
Kamikatsu, a Japanese village, has already gone Zero Waste. The 2,000 villagers recycle (循环利用) everything possible. There are 34 different boxes at the recycling center! The villagers sometimes just feel unhappy about what they have to do, but they also see the good side.
Let’s think about how to enjoy a Zero Waste Christmas. By sending recyclable cards, we can help our friends and family reduce waste. And wouldn’t it be better to enjoy the spirit of Christmas with a real tree that can be re-planted in spring?
Going Zero Waste requires us to think more about what happens before and after we act. It is not always easy. But just think how good it would be, both for ourselves and for the environment, if we never had to waste anything.
1. The underlined word “it” in Paragraph 1 refers to .| A．a plastic bag | B．the rubbish |
| C．a difficult thing | D．going Zero Waste |
| A．Planting trees at Christmas. |
| B．Using plastic bags when shopping. |
| C．Sending recyclable cards for Christmas. |
| D．Buying food when you are very hungry. |
| A．To persuade people to reduce waste. |
| B．To teach people how to enjoy Christmas. |
| C．To introduce the life of Japanese villagers. |
| D．To tell people how to deal with difficulties. |
| A．Topic—Examples—Discussion |
| B．Examples—Argument—Topic |
| C．Topic—Explanation—Argument |
| D．Examples—Explanation—Discussion |
