【推荐1】After two years of circling Bennu, an ancient asteroid (小行星) hundreds of millions of kilometers away, a NASA spacecraft made its way to the rocky surface and collected samples.

NASA spacecraft OSIRIS-Rex was launched in 2016 with the goal of getting samples from the asteroid. On Oct 20, 2020, it was confirmed that 60 grams of rocks had been collected, marking the biggest haul (一次性收获) from beyond the moon.

The spacecraft dropped out of its 750 meter-high orbit and took about four hours to carefully and slowly make it to just above the surface. The OSIRIS -Rex’s 3.4 meter arm, which is responsible for collecting samples, reached out and touched Bennu for about 10 seconds. During the brief touch-down, the spacecraft blasted Bennu’s surface with nitrogen (氮) gas. This stirred up dirt and rock that could then be collected by the arm’s sampling head.

The work behind this process was much trickier than expected. Before OSIRIS-Rex’s launch, data from multiple telescopes showed the asteroid’s surface looked like a beach, full of tiny particles (颗粒) that could be easily collected. However, when OSIRIS-Rex got close enough to take a close-up of Bennu, scientists were surprised by how rough it was and how large the rocks were. The rocky terrain (地形) brought unexpected risks for the spacecraft, so they had to adjust the original plan. The scientists had to add extra software to the spacecraft. Also, they extended the mission time and spent extra time creating a 3D map for Bennu’s surface.

They didn’t have a lot of room for mistakes since OSIRIS -Rex only has three bottles of nitrogen gas. Luckily, after two drills, the spacecraft managed to successfully collect over 60 grams of material.

The sample seems like a small piece of Bennu, but it is a big step for mankind. Bennu was chosen for a reason. The big, black, round, carbon -rich asteroid, which was formed about 4.5 billion years ago, witnessed the solar system’s entire history. With the sample, scientists will explore deeply in labs to find out more secrets about our solar system.

1. The 3^rd paragraph is mainly developed _________.

A．by example	B．by process
C．by comparison	D．by statistic

2. What does the underlined word “trickier” in paragraph 4 probably mean?

A．more convenient.	B．more necessary.
C．more challenging.	D．more surprising.

3. Which of the following is true according to this passage?

A．The rocky terrain brought risks for the spacecraft to adjust the original plan.

B．It is meaningful for the spacecraft to collect samples successfully from Bennu.

C．The carbon-rich asteroid must have witnessed the existence of ancient life.

D．We have found some secrets about our solar system by analyzing the sample.

4. What would be the best title of this passage?

A．Asteroid Investigation	B．A Space Exploration
C．Making Our Way To Bennu	D．Secrets About The Solar System

【推荐3】Environmental pollution and other human activities are leading to thousands of deaths among seabirds, a new study has warned.

Ecological experts tracked the behavior of British and Irish seabirds. They used satellites to track hundreds of the creatures to find out where they went to catch fish at sea. The study can help assess potential impact from human activities and where protected areas of the seas should be.

Lightweight GPS tags were fitted to more than 1,300 adult birds from 29 different colonies around the UK and Ireland, including kittiwakes, shags, razorbills and guillemots. Results from the five-year study show the large areas of sea the four seabird species use. They found it was at least 600,000 square miles, an area three times the size of Spain. It shows how far they travel from their nests in search of food for their chicks. And it shows the use of the seas by all four species concentrated in the coastal waters of Scotland, highlighting the importance of conservation measures there.

The four species studied require conservation help, with kittiwake numbers declining 71 percent in the past 25 years and shag populations down 61 percent. This means both seabirds are "red listed" and need urgent protection. Razorbills and guillemots are "amber listed", which means they are considered to need conservation action.

Dr. Ewan, lead author of the research, said, “Many seabirds are at the top of the marine food web. They feed on some small fish but that prey is declining because of human pressures, including climate change. The result is that thousands of sea baby birds are dying each year because their parents can't feed them. For the first time, this study provides us with a full map for the feeding areas for some of our most important seabird species.”

The analysis provides critical data to inform marine management, the experts said.

1. Which is one of the purpose of the study?

A．To find out where to catch more fish.

B．To judge which sea should be protected.

C．To know the seabirds’ impacts on human beings.

D．To study the behaviour of British and Irish seabirds.

2. How did the experts track the seabirds?

A．With the help of satellites.	B．With help of the fishermen.
C．By observing human activities.	D．By tying GPS tags on the ship.

3. On which coast would most tracked seabirds gather?

A．France.

B．Ireland.

C．Spain.

D．Scotland.

4. What’s Dr. Ewan’s attitude towards the research?

A．Puzzled.

B．Doubtful.

C．Positive.

D．Disappointed.

【推荐1】According to a large study of activity levels and arthritis (关节炎) pain, there seems to be no link between the amount of exercise people do and whether they develop painful osteoarthritis in their knees. But the research couldn’t rule out that high-impact forms of exercise like running bring on the condition.

Osteoarthritis is more common as people get older and is sometimes called a “wear and tear” condition. Arthritic knees often have obvious damage to their cartilage which covers and protects the ends of bones.

Earlier studies have found conflicting (矛盾的) results on whether exercise can make arthritis more likely. So Lucy Gates at the University of Southampton in the UK and her colleagues joined together the results of six such studies, which over 5,000 people took part in who firstly had no knee pain or other sign of arthritis.

At the beginning, people were asked about how much exercise they did, including playing sports, walking and cycling. They recorded the general time spent exercising each week, and their activities were graded by their metabolic equivalent, or MET (代谢当量) scores, a standard way of dividing activities into different types according to how much they raise a person’s metabolic rate.

At the end of the studies, which lasted from five to twelve years, people were also asked if they had developed knee pain or arthritis. The probability of developing arthritis wasn’t associated with activity levels, either by how much time people spent exercising each week or by their total time and MET scores.

“There’s more work to be done on telling apart risk and different types of activity,” says Gates. “The next step is to figure out how different weight-bearing activities might change things. We can’t say there’s no relationship there,” says team member Thomas Perry at the University of Oxford.

1. What is the finding of the large study?

A．Too much exercise leads to arthritis.

B．Arthritis is common among old people.

C．Sports-loving persons are in better health.

D．Exercise may not be responsible for osteoarthritis.

2. What made Lucy Gates and her colleagues do the large study?

A．Their love for exercise.	B．The goal to treat knee pain.
C．The results of earlier studies.	D．Their care for those 5,000 people.

3. How did Lucy Gates and her colleagues do the large study?

A．By studying the cause of pain knees.

B．By tracking and recording for a long time.

C．By asking people to fill in online questionnaires.

D．By grading and recording people’s metabolic rates.

4. In which column of a newspaper may this text appear?

A．Education.

B．Jobs.

C．Sports.

D．Arts.

【推荐3】Nobody was watching Ahmed Hafnaoui at the beginning of the swimming race. But all eyes were on the 18-year-old Tunisian（突尼斯的）teenager at the finish.

“When I touched the wall and I saw myself first, I just couldn’t accept that—it was too unbelievable,” said the teenager, who became the unexpected winner of the 400-meter freestyle at the Tokyo Olympic Games on Sunday.

When asked how he kept his lead, he simply said, “I don’t know. I just put my hand in the water. That’s it. ”The swimmer seemed at a loss for words. Shaking his head, he said, “It’s a dream that has become true. ”

Hafnaoui came into the race with the slowest speed of the eight swimmers—but he touched the wall first, beating out Australia’s Jack McLoughlin by just 0.16 seconds. Kieran Smith from the US took bronze（铜牌）, about a half-second behind the winner.

The teen is the North Africa country’s fourth Olympic gold winner. He’s the second-youngest athlete from an African nation to win a swimming gold; Joan Harrison of South Africa was 16 when she won the 100 backstroke（仰泳）at the 1952 Helsinki Games.

Hafnaoui began swimming at age 6 when his father sent him to a swim club. His limited international experience includes an eighth-place finish in the 400 freestyle at the 2018 Youth Olympics in Buenos Aires.

Standing on the podium（领奖台）, Hafnaoui felt really excited. “I was in tears because when I saw the flag of my country and I heard the national song in the background, it was great, ” he said. “I’m so proud of it. ”

Hafnaoui has another chance to pull off a surprise when he competes in the 800 freestyle on Thursday. Next year, he said he plans to attend college in the US.

1. Who won the 100 backstroke at the 1952 Helsinki Games?

A．Kieran Smith.	B．Joan Harrison.
C．Ahmed Hafnaoui.	D．Jack MeLoughlin.

2. What can be learned about Ahmed Hafnaoui?

A．He began his training at a very early age.

B．He feels confident to win the 800 freestyle.

C．He is the fourth-youngest athlete to win a gold.

D．He had rich international competing experience.

3. How did Ahmed Hafnaoui feel at the award ceremony?

A．Calm.	B．Ashamed.
C．Sad.	D．Proud.

4. What is the best title for the text?

A．Ahmed Hafnaoui Is Ready to Make History at Tokyo 2020

B．The Swimming Star Ahmed Hafnaoui Plans to Study in the US

C．A Young Tunisian Shocks the Swimming Field at Tokyo 2020 Olympics

D．The Youngest World Champion Shares His Secret to Lead the 400 Freestyle