1 . Many of the world’s islands were previously unexplored places, but over time, people have come to these places with far-reaching effects, including deforestation, over-hunting and the introduction of invasive species. _______, most of the bird species disappeared.

While the death of many birds since the 1500s has been _______, our knowledge of the fate of species before this relies on fossils (化石), and these records are limited because birds’ lightweight bones are _______ over time. This conceals the true _______ of global extinctions.

Researchers now believe 1,430 bird species — almost 12 per cent — have died out over modern human history since around 130,000 years ago, with the vast majority of them becoming extinct directly or indirectly _______ human activity.

The study, led by the UK Centre for Ecology & Hydrology (UKCEH) and published in Nature Communications, used statistical modelling to _______ the undiscovered bird extinctions.

Lead author Dr Rob Cooke, an ecological modeler at UKCEH, says:“Our study demonstrates there has been a far higher _______ impact on diversity than previously recognized. Humans quickly destroyed bird populations through habitat loss, over-exploitation, and the introduction of rats, pigs, and dogs, which attacked the birds’ nests, and _______ with birds for food. We show that many species became extinct before written records and left no _______, lost from history.”

Dr Søren Faurby of the University of Gothenburg, a co-author of the study, adds: “These historic extinctions have had a major impact on the current biodiversity crisis. The world may not only have lost many fascinating birds but also their varied ________ roles, which are likely to have included key functions such as pollination (授粉). This will have had knock-on effects on ecosystems, so, ________ bird extinctions, we will have lost a lot of plants and animals that ________ these species for survival.”

Observations and fossils show 640 bird species have been driven extinct — 90 per cent of these on islands ________ by people. These ________ from the iconic (标志性的) Dodo of Mauritius to the Great Auk of the North Atlantic to the lesser-known Saint Helena Giant Hoopoe. But the researchers estimate there have been further 790 unknown extinctions, meaning a total of 1,430 lost species — leaving just under 11,000 today. Therefore, from the perspective of protecting species ________, the protection of birds is an urgent issue for mankind.

2 . The misery of my bike commute in Calgary, Alberta, is the river valley hill. It’s not particularly steep, but at about a mile long, I rarely climbed up without arriving with sweat. Studies have shown the prospect of arriving at work sweaty is one of the biggest _________ to getting would-be bike commuters out of their cars. That’s especially true in a city like Los Angeles, where _________ may face long routes , hills or hot streets with a lack of shade.

“Pedelec”, or pedal electric-assisted bikes like the one I rode, can end that worry. They look and act like traditional bicycles, but their motors make pedaling much easier when required. Sometimes called the most energy-efficient motorized mode of transportation ever built, they’re also incredibly green. The biggest barrier may be the outdated attitude that sees bikes only as a recreational athletic opportunity rather than a practical _________ option.

At a time when cities across North America are struggling to combat crippling traffic and reduce climate emissions, e-bikes have the _________ to ease the both problems. And yet ridership has yet to truly _______.About 152,000 e-bikes were sold last year in the U.S., a figure that would be more than 5 million if Americans used them at the same rate as western Europeans.   

Many of the barriers to e-bike _________in North America are legislative. Patchwork rules treat e-bikes more like mopeds than traditional pedal bikes in some jurisdictions,meaning they are _______from bike lanes and from boarding public transportation.

Few places on the continent, _________, are better poised to break through barriers than California. Legislation was approved last year to encourage e-bike use, by legally differentiating the cycles from mopeds. In an attempt to head off worries about turbocharged machines flying down sidewalks and bike lanes at unsafe speeds, the law classifies bikes into different tiers to _______ lower-speed e-bikes, which top out at 20 mph, from faster-moving “speed pedelecs”, which are restricted from protected bike paths.

Amid these legislative ________, e-bikes have become more accessible to consumer. Finding them in bike shops isn’t as __________ as it once was, and their cost has fallen as the price of lithium-ion batteries has dropped. Today, a decent e-bike, while still __________, is comparable in price to a high-end mountain bike. After years of ____________over mixing pedal and motor power, cycling advocacy organizations also are finally throwing their support behind e-bikes. Dave Snyder, the executive director of the California Bicycle Coalition, __________ the state’s new legislation based partly on the __________that e-bikes help out those who“just can’t ride as far or as fast as they need to”.

It is perhaps the most ironic symbol of the life on our planet. The Amazon is the world’s largest and most bio-diverse tropical rainforest and a huge trap for carbon dioxide. The harms of _________ in this vital resource are old news. But now, the time on the clock is running out. It seems that the world’s biggest rainforest is about to turn into the world’s biggest environmental _________. “We are about to collapse,” says Luciana Gati at Brazil’s National Institute for Space Research. “We are in a(n) _________, we need action now.”

Gati has spent years _________ the Amazon from the air. She believes we are as little as five years from a point of no return, where rainforest begins to turn into dry land. It is also the point at which billions of tons of carbon would be _________ into the atmosphere. “It’s a nightmare,” she says.

That nightmare situation is the well-known Amazon _________ point, where the ecosystem can no longer cope with the damage of the forest cutting. Like a domino game, one brick falling will _________ the whole tower to collapse in a heap.

Warnings that this is approaching have now taken on extreme urgency. The rate of deforestation has increased sharply and is fast approaching the theoretical _________. In September, a group of more than 200 experts, including Gatti, released an assessment of the situation. The conclusion: we are on the _________ of disaster.

Scientists first began to seriously worry about a potential Amazon tipping point in about 2000, when some studies warned that a combination of climate change and deforestation could cause the rainforest to __________.

A few years later, a team of Brazilian scientists put numbers on it. They __________ that in central, southern and eastern parts of the Amazon, a loss of 40% of the forest cover from pre-industrial levels, or 3°C warming would reduce rainfall so much that the rest of the forest would die of __________ and turn into a dry land in less than a decade.

The scientists have since __________ that prediction, partly due to the global warming that has happened since 2000. The Amazon is already 1.2°C warmer than it was in pre-industrial times and is warming three times faster than the global __________. At that rate of warming, between 20 and 25% deforestation would be enough to dry up the land and destroy the Amazon completely.

“Either way, we would be wise not to exceed 20%”, says a scientist, “for the commonsense reason that there is no point in __________   the precise point of limit by tipping it.”

4 . Global surface temperatures last month were 2.25 degrees warmer than the 20th century average of 60.1 degrees, breaking previous records, from August 2016, by more than half a degree, according to NOAA researchers. “That to me is a really huge _______ from one record to the next,” said Ellen Bartow, a physical scientist with NOAA’S National Centers for Environmental Information.

The report _______ what millions of people have experienced in recent months, including record-breaking heatwaves that have touched almost every corner of the globe. Asia, Africa, North America and South America had their warmest August on record, as did the Arctic, Europe and Oceania — a region that _______ Australia - had their second-warmest August on record, the report said.

It wasn’t just the land that _______ : August set a record for the highest monthly sea surface temperature abnormally—1.85 degrees above average. The warming oceans _______experiencing its fourth continuous month with the _______ shrinking sea ice, with Antarctica sea ice extent on record. Globally, sea ice extent in August was about 550,000 square miles less than the previous record low, set in August 2019.

“We’ve seen unheard-of warmth in the global ocean, and that’s definitely alarming because its effects _______ beyond just the scope of the ocean,” Bartow-Gillies said. “Not only are you _______ marine habitats, but you’re affecting storm creation, you’re creating more instability in some areas, and you’re creating flooding events in other areas. There’s a whole host of _______ that come along with these warmer ocean surface temperatures that we’re seeing.”

In fact, the report comes after a series of severe natural ________ that span the globe. This week, a Mediterranean storm caused serious flooding in Libya, killing more than 11,000 people. In Canada, wildfires burned through more than 42 million acres of forests this summer, and several are still burning. ________ global warming was not the singular cause of any of these disasters, heating of the Earth continues to ________ the likelihood of extreme weather events and wildfire worldwide.

“The scientific evidence is ________ —we will continue to see more climate records and more intense and frequent extreme weather events impacting society and ecosystems, until we stop ________ greenhouse gases,” read a statement from Samantha Burgess, deputy director of the European Union’s Copernicus Climate Change Service, which also ________ that this summer was the hottest on record.

5 . How to Care for Your Tree

1. Water the newly planted tree. Once the tree is planted, water it and keep up a _________ schedule of watering.

Water the tree every day for several weeks to let the _________ get established in the surrounding soil. After this you can reduce the frequency of watering.

Water as necessary for the conditions in your area. _________ humidity into consideration to help you decide _________ to water your tree.

If you are planting fruit or nut trees for a small home orchard, continue to water weekly for the _________of the tree, as your crop depends on consistent irrigation. You’ll also want to fertilize fruit and nut trees monthly, or _________ package directions.

2. Use mulch (覆盖物). Considering adding a layer of mulch _________ your tree to help keep moisture in and weeds out.

Cover the planting hole with 1-3 inches of shredded hardwood or leaf mulch. Keep the mulch at least 12 inches away from the trunk _________ it may cause the trunk to rot.

Mulching around the tree will _________ the tree from trampling and lawnmowers, __________ are two activities that commonly kill young trees.

3. Prune the tree if necessary. If there are any broken, dead, or diseased limbs on your tree,   __________ them gently with knife. If there is nothing wrong with the tree, there is no need to prune it until after the first growing season.

4. Enjoy the tree as it grows over the years. Appreciate its __________ and beauty and thank yourself for adding another tree to the world. You won’t regret it and __________ you properly care for it, the tree can grow long time!

You’ll need to make sure that you water your plant to keep it thriving. You want to achieve __________ of giving it enough water to penetrate (穿透) the roots while not drowning it.

Watering your tree with a steady stream from a garden hose for about 30 seconds should be sufficient. The soil should feel moist at all times and mulch will help retain the moisture.

Check soil moisture by digging about 2 inches below the surface and then use your __________ to test if the soil is moist. If it is, you don’t need to water.

6 . Sea levels along coastlines in the United States will rise about one foot by 2050, with larger increases on the East and Gulf coasts, according to a comprehensive new report by climate scientists.

Oceans have already risen about one foot in the last century, as climate change melts glaciers (冰川) and ice caps around the world. But the pace is ______ scientists warn, and the next 30 years will see the same amount of sea level rise as the previous 100.

The report gives the most concrete and certain sea level ______ ever published for the U.S. And advances in computer models and real-world information about rising seas make it possible to see the future more ______ than ever.

Sea level rise ______ dramatically for different parts of the U.S. coast. The ocean is not like a bucket of water that rises at the same time as more liquid is ______. Ocean ______ push more water into some areas than others. Ice in different regions melts at different rates. In many parts of the world, sea level rise is ______ because coastal land is sinking.

The new report adds up all those factors to give ______ estimates for different parts of the U.S. The authors predict about a foot and a half of sea level rise for the Gulf Coast by 2050, with particular hot spots from Texas to Mississippi, where exploitation of underground oil, gas and drinking water is causing the land to rapidly _____ into the rising ocean water. There are ______ hot spots in the Mid-Atlantic region, including Annapolis, Md. and Norfolk, Va. Overall, the East Coast is ______ to experience a little more than a foot of sea level rise in the next 30 years.

Sea level rise is happening more ______ on the West Coast, including much of southern and western Alaska, the report finds. The authors predict about six inches of sea level rise by 2050.

William Sweet, a sea level rise expert with the National Oceanic and Atmospheric Administration (NOAA) and one of the authors of the new report, says cities that are not yet flooded should ______ now. Quickening sea level rise may require that humans ______ where and how we build homes, offices, roads and anything else that is better dry than wet. Right now, development in flood-prone (易发洪水的) areas is increasing, despite climate change.

Beyond 2050, the report makes clear that humans have a ______: reduce greenhouse gas emissions and control sea level rise, or keep burning fossil fuels and face oceans that are two, three or even 10 feet higher than today.

7 . In Mumbai, there’s the ceaseless clamor of car homes as drivers edge through traffic. There’s pounding and buzzing from the construction of office towers and apartment blocks. Drumbeats and trumpet melodies spill out from weddings and countless festivals. And it’s all topped off by bellowing (大声吼叫的) street vendors and garbage trucks blasting Bollywood songs. Living in Mumbai requires a huge ______ for noise.

When Sumaira Abdulali began campaigning against noise pollution in India’s financial capital two decades ago, friends, acquaintances and even her lawyers insisted it was ______ . “People told me it’s foolish to even try, because Indians love noise,” she says. “We’re a noisy country.”

But in 2003, Abdulali won a lawsuit seeking to ______ environmental rules that had allowed loud music late into the night during a festival. ______ , the victory led to a ban on loudspeakers within 100 meters of schools, hospitals, courts and places of worship. And she has since won more than a dozen other actions both on her own and via the Awaaz Foundation (awaaz means “noise” in Hindi), which she launched in 2006.

The World Health Organization warns that noise is a top threat to human ______ , affecting not only hearing but also sleep, brain development and cardiovascular health. Abdulali claims Mumbai is the world’s ______ city. A study led by Ritesh Vijay, an expert from India’s National Environmental Engineering Research Institute, did find that noise levels in Mumbai and surrounding areas in 2020 dramatically exceed legal limits.

In recent years, the battle against noise has become increasingly ______ , with Abdulali often facing powerful interests who consider it an inevitable byproduct of growth. With increasing ______ , ever more people are exposed to continuous noise. In a rapidly expanding city such as Mumbai, with a population topping 12 million, demand for housing puts noise rules ______ development plans. Although sound barriers are required for construction projects, they’re expensive, so developers ______ installing them.

Traffic is a tougher problem. Noise on the road can reach 110 decibels (分贝) — a level that can lead to permanent hearing damage after just 15 minutes of exposure, according to the US Centers for Disease Control and Prevention. Luckily, ______ can help in the fight, Vijay says. He suggests devices that measure horn use, which would let officials offer ______ drivers rewards like deductions (扣除) on car insurance. Dynamic signaling, where sensors linked to stoplights detect traffic density, would improve vehicle flow and ______   the urge to resort to horns, he says. Local government also ______ . Mumbai decreed (颁布) India’s first “No-Honking” day in 2008, with police handing out booklets to raise awareness about traffic noise and imposing fines up to 1,000 rupees ($12) on offending motorists.

Far more important is the longer-term impact of the day-to-day noise, so that’s where Vijay believes activists should focus their energy. “In India we celebrate festivals with lots of noise,” he says. “But our ______ noise itself is beyond the allowed limit.”

8 . To prevent tsunami-caused disasters, several countries worked together to expand the use of a tsunami-detecting system that had been developed in the United States by the National Oceanic and Atmospheric Administration (NOAA). The system________ of an instrument installed on the seafloor — called a tsunameter — that measures pressure changes caused by a passing tsunami. The tsunameter sends a signal to a surface buoy (浮标), which sends the data to a satellite, which ________ the information to warning centers around the world.

By 2004 only six such detectors had been installed, all in the Pacific. There were________ in the Indian Ocean, and many countries in the region had no national warning centers that could have ________ local communities. That policy mistake had tragic consequences. In Sumatra people had only a few minutes to run, ________the tsunami took two hours to reach India, and some 16,000 people died there. “It was totally unnecessary,” says Paramesh Banerjee, a geo-physicist at Nanyang Technological University in Singapore. “Technically it would have been relatively ________ to install a tsunami warning system for the Indian Ocean.”

There are now 53 detector buoys operating in the world’s oceans, including 6 of a planned 27 in the Indian Ocean. So a (n)________ of the 2004 horror, in which the tsunami traveled for hours and still caught people by ________ is less likely. But buoys would not have helped in Sumatra. People living on coasts near a rupturing fault (地壳断层) can’t wait for ________ that a tsunami is on its way, which it often isn’t; they must flee as soon as the quake hits. The Japanese warning system relies not only on tsunameters but also on seismometers (地震测量仪) — a thousand of them ________ the country, the densest network anywhere — combined with a computer model that forecasts the scale of a tsunami from the magnitude (震级) and ________ of the quake.

In March, the system, which is run by the Japan Meteorological Agency (JMA), did not work perfectly. JMA’s initial ________, while the ground was still shaking, put the quake magnitude at 7.9 — but later analysis revealed a quake that, at magnitude 9, was 12 times larger. The tsunami forecast warned of waves of ten feet or more — but they reached 50 feet in Minanisanriku and in some places even ________. But the human ________ to the warning was imperfect as well. “I think this time many people who lived above the high-water mark of the 1960 tsunami didn’t bother to run.” says Jin Sato, mayor of Minanisanriku. “Many of them died.” The town’s seawall, he thinks, also gave people a false sense of ________

9 . Why Go To London

The English writer Samuel Johnson famously _________, “When a man is tired of London, he is tired of life, because the city can provide wonderful experience.” More than two centuries_________ since Johnson’s era, but his words are still true. This is because life in London is nothing short of wonder, and travelers find that one visit isn’t enough to experience everything that this two-millennia-old city offers.

In London, when you walk into the opera house, you may find that Shakespeare’s works_________ by actors. While Londoners still praise the power of tea, they_________(make) room for some Starbucks here and there, and pressed juice too. In all, London’s culture is always aimed to what’s next. _________(discover) it all on one of London’s best tours.

10 . Is global warming killing the Maldives?

The Maldives is one of the most beautiful countries in the world. Every year, millions of _______ go there to enjoy the wonderful _______. And in recent years, more and more people would like to visit it, why? Because the little island country is _______. If global warming  _______ , say scientists, the country will go _______ into the ocean within 100 years. That means the Maldives might have _______ by 2100.

The Maldives lies in the Indian Ocean. It is the _______ country on earth—its highest point is only 2.4m above sea level. _______ greenhouse gas emissions(排放), sea levels will _______ between 9cm and 88cm by 2100. If scientists are  ________, most of the Maldives will be covered with water in years.

Last October, Maldivian President Mohamed Nasheed and his cabinet(内阁)held the world’s first underwater cabinet meeting to make the world ________ the terrible consequence from global warming to their own country. In December, he________ at the 2009 United Nations Climate Change Conference(大会) in Copenhagen, trying to ask for ________ from the world for his country. The president even has a   ________ to buy a new homeland and move his country and people to a new place.

The Moldavian government has been doing all to fight the ________ . But the fate of the islands is in the world’s hands. No one wants to see this little island country disappear from the world.