①Swifts live mostly in the air. These small birds are among the fastest animals on Earth. In fact, swifts can go two or three days without touching the ground! To get used to life in the sky, swifts use their speed and the saliva in their mouths.

②Swifts can fly faster than 100 miles per hour. That’s because their wings are like boomerangs. This shape of the wings helps them to fly much faster. They can also move one wing faster than the other, which allows them to make sharp turns without slowing down. Making fast, sharp turns helps swifts catching flying bugs to eat.

③The saliva helps swifts catch bugs to feed their young. It is sticky, like glue. Swifts often fly into clouds of bugs such as mosquitoes and open their wide mouths to catch as many insects as they can. The bird collects insects in its mouth graduallyand holds the insects in a sticky ball of saliva. One food ball can contain nearly 1,000 bugs.

④Swifts also use their saliva as glue to build their nests. The birds catch feathers in the air and stick the feathers together to build a strong nest on the side of a cliffor building. Swifts’ short feet are not good for walking or standing on land for long. But their sharp claws allow them to stick to rocks and walls so they can take a brief rest before returning their lives in the sky.

A．	B．
C．	D．

5 . On March 14, Bai Xuesong, a guide at the Beilin Museum in Xi’an, northwest China’s Shaanxi province, hosted a live broadcast displaying the collections at the museum.

Bai has become a hit on the Internet ever since he started giving tours of the museum collections through live streaming videos on February 23. After viewing his broadcasts, many netizens expressed a desire to visit the museum when it reopened after the COVID-19 outbreak.

It is estimated that more than 30 museums in China, including the National Museum of China and the Dunhuang Academy China, have hosted live broadcasts on online platforms during the epidemic, each gaining over 10 million viewers in one day. The Gansu Provincial Museum, one of the museums that has been exploring online platforms and using them, owned as many as 900,000 viewers at one point in its live broadcasts, more than half of its total viewers last year, according to the deputy curator(副馆长)of the museum. As a result, the number of fans of the official online store of the museum on the e-commerce platform Taobao has grown to 25,000, with sales of related products seeing a huge increase.

“Cooperation between museums and Internet platforms is beneficial to both sides,” said Huang Yang, vice professor with the cultural heritage and museology (department of the Nanjing Normal University). He said that while museums need to use live broadcasts to spread culture, Internet giants need the resources that museums possess to provide high-quality content for users. ▲ .

6 . ①Anyone watching the Winter Olympics in Beijing, China over the last few days has seen lots and lots of snow—man-made snow. No other cities have held the Winter Olympics on almost 100% artificial snow before.

②This year’s Winter Olympics was held in Beijing, China, and in two areas northwest of Beijing, Yanqing and Zhangjiakou. The areas get cold in winter, but they don’t get a lot of natural snow. That’s because they’re close to the Gobi Desert, and are generally very dry.

③That meant _______. China took water from a reservoir which helps supply Beijing’s drinking water and sent it to a nearby river. To carry the water to the mountains for making snow, the country ran miles and miles of pipes. China says making the snow took about 49, 000 gallons of water. Outside experts say it probably took a lot more water than that.

④China paid an Italian company called Techno Alpin to make the snow. Techno Alpin made artificial snow at several earlier Winter Olympics. For the snow in this year’s Olympics, Techno Alpin laid over 40 miles (64 kilometers) of pipes and brought in hundreds of snow-making machines. Even with all those machines, making the snow for this year’s Games took seven weeks.

⑤In recent years, it has become more and more common to use artificial snow at winter sports events. That’s true even in places that used to have a lot of snow naturally. Some artificial snow was used in the Winter Olympics in 2010 and 2014 because of warm weather. In the 2018 Games in PyeongChang, South Korea, almost 90% of the snow was man-made. As the world warms because of climate change, problems like this are expected to become far more common. Michael Mayr, who leads Techno Alpin in Asia, says, “You could not have winter sports now without man-made snow.”

It’s hard to know how much active you need to stay healthy, isn’t it? That’s why the workers of Google Fit have worked with the World Health Organization (WHO) and the American Heart Association (AHA) to bring you Heart Point.

Heart Point is an activity goal. It can help you improve your health, and it is good for your heart. When you are walking, running, riding or doing some other sports, Google Fit is able to record it. Then, it can give you a report about your health. Even when you are sleeping, it can keep a record and give you some advice. Doing some activities will make your Google Fit heart go faster and is good for your health. You’ll win one Heart Point for each minute of moderate activity. For example, it can be faster when you are walking your dog. And you’ll get double Heart Points for more intense activities like running, hiking and playing basketball. It’s not hard to get the right amount of physical activity. It takes just 30 minutes of walking, five days a week to complete the activity you need. This amount of exercise is enough to make you less likely to have heart disease.

“It’s great at recording steps. I walk about 10,000 steps every day. The app seems to record really exactly as I start and stop the workout. There are fewer records of workouts such as riding a bike. But all in all, it’s a great app and I like using it very much,” says Alan Brockett from the US.

What kind of movie would you like to watch? Today let me introduce an old but fantastic movie to you—Avatar. It was directed by James Cameron. It took 14 years to prepare for the movie and four years’ time to film it. It was first shown on January 2nd, 2010 in China. It cost 500 million and it cost the most money in history of making films. This is a great deal of money.

This movie is very popular with children and adults like it, too. Now I’ll tell some details to you. In the future world, to discover and get the mineral resources on the planet Pandora, people open up the programme Avatar. They mix humans’ and the Na’vi’s DNA together to make a new kind of man Avatar. They want Avatar to get the mineral resources from Na’vi’s villages and send them to the Earth. Jake receives this Avatar programme and goes to the planet Pandora. He gets to know Neytiri, the princess of Pandora, who falls in love with him because of his bravery. Then he faces the choice between humans and the Na’vi. What do you think of it after my introduction?

Avatar has passed Titanic to become one of the biggest grossing movies in the world. It has won the Golden Globe and the Oscar. If you haven’t watched it before, you can watch it at once!