Scientists often compare coral reefs to underwater rainforests, yet unlike the leafy plant base of a forest, corals are animals.The soft organs inside the hard parts of corals are naturally transparent and get    1    (they) famously brilliant color from algae(藻类）living inside them.

When corals experience stress from hot temperatures or     2     (pollute),they end their interdependent relationship with this algae,typically forcing them out     3    turning white, though one recent study indicates some corals turn a bright neon color when stressed.Corals are still alive when they bleach(白化），but they're     4     risk-essentially immunocompromised(免疫功能低下）－and many     5     (eventual) starve and die, turning a dark brown.

People first noticed coral bleaching events in the 1980s.The problem worsened in 2016, when an El Nino weather pattern,     6    causes warmer waters in the Pacific Ocean,     7    （mix) with an already unseasonably warm ocean and killed off a third of the corals on the Great Barrier Reef.Since then, roughly half the corals on Australia's famous reefs     8    （die) in following bleaching events, risking an underwater landscape 1,500 miles long.

Scientists around the world are looking for all kinds of ways to protect and maybe even revive corals.One option is     9     (create) more marine protected areas-essentially national parks in the ocean.Scientists say creating marine shelter, where fishing, mining,and recreating are off limits, makes the reefs     10     (healthy), and so much stronger.

Many people know that marine mammals，like whales and dolphins，breathe air as we do.    1    , many people don't know that they have developed some interesting sleeping     2     (habit) to adjust to their regular trips up to the surface for air.

    3     ( like ) our own breathing，which does not require any effort，marine mammals must consciously go to the surface of the water    4     ( breathe) through a blowhole on top of their heads. Because of this，they don't sleep for    5     solid 8 hours a night like we do.

Some marine mammals sleep while    6     (swim ). Whales nap for brief periods，during    7    an alert(警觉的）friend guides them. In fact, a young whale must sleep alongside its mother because the mother's slipstream actually pulls the calf along.

Others，like dolphins，sleep while floating on the surface of the water or take short catnaps while floating below the surface.Researchers claim that when they sleep，their brain is always    8    ( partial) alert.Aside from these brief naps，dolphins are active most of the night.

Of course，marine mammals    9    ( equip) to handle underwater sleeping. They have    10    ( large)lungs，exchange air more fully at each breath， and carry more oxygen in their blood than we do, so they can hold their breath long enough to sleep with the fishes.

Huanglong is a beautiful natural area in the northwest part of Sichuan, China. It     1     (locate) in the southern part of the Minshan mountain range, 370 kilometers from the capital, Chengdu. The Huanglong Valley is a special     2    ( attract) here.

Huanglong     3     (get) its name from the river looking like a huge golden dragon in ancient times. It's actually a chain of     4     (pool) that flow through the valley. It runs 2. 5 kilometers to the north. In Huanglong, the soft mineral,     5     is colorless or white, formed a type of rock over thousands of years. This mineral gives the water its     6    ( variety) shades of green, blue, brown_? and     7    ( main) yellow. The waterway with its jewel-colored pools flows between peaks covered with snow like a great yellow dragon     8     (wander) through the mountains. There are about 3,400 of these natural pools throughout the valley .

All, however, are only for viewing. In order to protect the landscape, visitors are not encouraged     9     (go) into the water. As Huanglong is also home     10     several endangered animals, including the panda and the Sichuan golden monkey, hunting and hiking are forbidden here.

Cities usually have good reason for being where they are,     1     a nearby port or river. People settle in these places because they are easy to get to and naturally suited to communications and trade. New York City, for example, is near a large harbor at the mounth of the Hudson River. Over 300 years     2     (it) population grew gradually from 800 people to 8 million. But not all cities develop     3     (slow) over a long period of time. Boom towns grow from nothing almost overnight. In 1896, Dawson, Canada, was unmapped wilderness (荒野). But gold     4     (discover) there in 1897, and two years later, it was one of the largest cities in the West, with a population of 30,000.

Dawson did not have any of the natural conveniences of cities like London or Paris. People went there for gold. They travelled over snow-covered mountains and sailed hundreds of miles up icy rivers. The path to Dawson was covered with thirty feet of wet snow     5     could fall without warning. An avalanche (雪崩) once closed the path,     6     (cause) 63 deaths. For many who made it to Dawson,     7    , the rewards were worth the difficult trip. Of the first 20,000 people who dug for gold, 4,000 got rich. About 100 of these stayed rich men for the rest of their lives.

But no matter how rich they were, Dawson was never comfortable. Necessities like food and wood were very expensive. But soon, the gold that Dawson depended on had all been found. The city was crowded with     8     (disappoint) people with no interest in settling down, and when they heard there were new gold discoveries in Alaska, they left Dawson city as quickly as they     9     (come). Today people still come and go—to see where the Canadian gold rush happened.     10     (tour) is now the chief industry of Dawson City—its present population is 762.

Do you enjoy food, culture, entertainment, and shopping? You could be delighted at     1     (visit) Chinatown in Manhattan New York. New York’s Chinatown is     2     (convenient) located right next to Little Italy on Manhattan Island,     3     is one of the largest surviving ethnic Chinese communities outside of Asia. There are a number of     4       (landmark) in Chinatown that tourists or locals can go to see when weather permits. Chinatown, along with Little Italy in New York,     5     (list) in a historic district on the National Register of Historical Places in 2010.

If you want to try delicious food, Chinatown might be the     6     (good) place to go. Not only do they serve a special plate of Garbage Fish, but they also can take out dishes that you have no idea     7     is in them but pleasing to your taste buds nevertheless.

If you enjoy history, you will find that New York’s Chinatown is rich     8     history, culture, and civilization. It has fun for all ages. Whether you’re in Chinatown for     9     (relax) and entertainment, or to stop     10     (grab) a bite to eat, there is always something exciting going on that might grab your attention.

California is burning! Wildfires have spread (传播) across the US state and smoke     1     (fill) its skies since Oct 23. Take the Kincade Fire in northern California for example. It forced 200,000 people     2     (escape) from its path within one week.

California has seen many     3     (wildfire) in recent years. Why is this? California has the perfect wildfire conditions, Park Williams,     4     is a US climate expert, told The New York Times. It has dry air and high temperatures from spring through late fall. At     5     same time, seasonal winds blow across the state every year,     6     (cause) the wildfires to spread quickly and last for weeks.

Global warming has also made the fires     7     (bad) than before. It has dried out the state’s trees and other plants, which makes them burn     8     (easy). There are also other causes for California’s wildfires.     9    , it’s humans that have caused 90 percent of them, according    10     the US National Park Service.

Turning Deserts to Oases

Miracles are occurring in northwest China where stretches of deserts are turning green with thriving trees and luxurious grass. Decades of efforts have resulted     1     victory in the battle against desertification and China has not only achieved the UN sustainable development goal of zero net land degradation by 2030 well ahead of schedule, but also reversed（逆转）the trend of desertification and sandification.

The eco warriors have come up with a series of     2     （success） practices to end desertification, like the farmers’ group in Minqin,     3     county in Gansu Province, northwest China. Their success in fighting the approach of the desert offers important experience for desertification prevention and treatment. It is also the Chinese     4     （wise） for global ecological management.

China has the largest desert area in the world, with the largest number of people     5     （expose） to deserts and sandstorms. It is home to eight major deserts and four major sandy lands, which cover one     6     （five） of its territory. The western and northwestern parts are     7    （serious） affected by desertification.

Since the founding of the People’s Republic of China in 1949，the government     8     （give） priority to the prevention and control of deserts,     9     is listed as one of the strategic missions of the nation.

Major ecological projects have been carried out to green the country. The Great Green Wall also known as the Three-North Shelter Forest Program, is the biggest tree-planting project in the world,     10     （create） a green barrier to keep the encroaching desert in the north at bay.

Temperatures around the world are rising. Many places     1    (experience) extreme weather events such as extreme heat since the start of the new century.

Scientists have shown all that is going to get even       2       (bad). They looked at cities in the north half of the planet. They     3     (especial) paid attention to those in the US.

According     4     simple geography, the cities near Canada have cool to mild weather. Those near Mexico       5     (be) hotter and more humid(潮湿的). However, things are going to look and feel a lot different in 2080.

The scientists created a weather model       6     (study) the weather changes in 2080. They considered two important points. One was the warming of the planet by 1.5℃ to 3℃ and    7     other was the increasing greenhouse gas levels. Unluckily, what the scientists found was     8     (surprise)! The cities in the north turned into ones in the south— about 500     9    (mile) south. For example, Washington, DC felt like Greenwood, Mississippi，and Mississippi felt like Mexico.

That’s bad news for people in the US,     10     it’s also bad for people everywhere because we’re all in the same boat.

Absolut Vodka, a brand of international wine & spirits giant Pernod Ricard, launched the new Absolut Nights 100 campaign—Comeback across China on Dee. 6 in Beijing, with a new comeback limited-edition bottle using creativity    1     ( drive ) recycling. The Absolut Comeback campaign attempts to pool creative nightlife ideas from young Chinese people to explore more possibilities.

Under the theme of “Comeback”, the new season of Absolut Nights 100 campaign encourages young    2    ( consume) not only to explore more possibilities with their creativity and artistic talent to open the world in different ways    3     also to make sustainability and recycling part of their lifestyle. Absolut Vodka launched a campaign to promote    4     ( recycle).

The limited-edition Absolut Comeback bottles, which     5     ( make) with more than 41 percent recycled glass, are launched simultaneously across China. For the first time, Absolut takes advantage of the bottles to spread    6     idea that everything can be recycled and reused, in an effort to inspire more people to reduce waste by unleashing their creativity.

Absolut Vodka's strategy has always been in consistence    7    Pernod Ricard’s commitment to sustainability. In April 2019, Pernod Ricard     8     (launch) its “2030 Sustainability & Responsibility Roadmap”, to further upgrade    9    (it) strategy in enabling sustainability.

In June 2019, Pernod Ricard China and the Institute for Sustainable Development Goals, Tsinghua University,    10    ( joint) released the first Sustainable Bar Operation Initiatives and Application Guidelines for China.

David Katz was upset by all the plastic going into the ocean. To help solve the problem, he had a     1    （create）idea to treat plastic like money. Mr. Katz calls his idea the "plastic Bank". The goal of the Plastic Bank is to use plastic to help people solve the problems     2    (gradual）. The Plastic Bank adds a value to plastic waste by paying people to recycle it.

The program began in 2015 in Haiti, a poor island nation with many     3    （problem）of waste plastic. The Plastic Bank has 30 "markets" in Haiti. At the Plastic Bank markets, people can exchange the plastic they've collected for     4    they need. The Plastic Bank markets sell lots of things that local people need. The stores also allow plastic collectors to use the money they earn to pay     5    health care or school.

To make sure that the plastic     6    （recycle）, the Plastic Bank works with partners, who agree     7    （use）the plastic that is collected. When customers buy these products, which are labeled "Social Plastic", they know that they are both helping people in other parts of the world     8    keeping plastic out of the ocean. So far, the Plastic Bank     9    （keep） about 7 million pounds of plastic out of the ocean. It makes a great     10    （contribute）to the ocean.