2 . In a study in the journal Science, researchers at Northwestern University in Illinois reported that they had developed an effective and inexpensive method for breaking down chemicals called poly fluoro alkyl substances (PFAS).

PFAS, first created in the 1930s, are chemical compounds (化合物). They are used to make a wide range of everyday products, including nonstick pans, carpeting, electronics, and fast-food wrappers. Once the chemicals are in the environment, they are almost impossible to eliminate because they are designed to avoid breaking down. Researchers have linked regular levels of exposure to these chemicals with several health problems, including liver damage, an increased risk of cancer, and reduced immunity.

Scientists had previously figured out how to remove PFAS from polluted water or soil but, until now, had no safe and effective way to destroy them once they were removed. The study reported that when the team boiled PFAS molecules (分子) with two common substances, the PFAS quickly broke down and became harmless.

In 2020, William Dichtel, a chemist and professor at Northwestern, read a study in which chemists at the University of Alberta, in Canada, found an easy way to break down chains of molecules. He asked a graduate student, Brittany Trang, to try the method on PFAS molecules.

Trang had spent months in the lab unsuccessfully attempting to pull apart PFAS, and at first she thought Dichtel’s idea was too simple to work. But she tried it, boiling PFAS with a common solvent (溶剂) called dimethyl sulfoxide (DMSO). Trang was shocked when the process destroyed the PFAS. She later mixed DMSO with a chemical called sodiumhydroxide and broke down PFAS even more quickly.

The scientists will work on ways to destroy PFAS outside the lab so large amounts of forever chemicals can be broken down at once. “It’s a huge challenge, but it’s in our grasp,” Dichtel told The New York Times. Scientists are also calling for a decrease in the amount of PFAS being released into the natural world. In June, the US government announced new plans to monitor PFAS, decrease the amount released into the environment, and address the effects of PFAS on human health.

1. What does the underlined word “eliminate” probably mean in paragraph 2?

A．Identify.

B．Destroy.

C．Remove.

D．Release.

2. How did William Dichtel find the way to break down chains of molecules?

A．He got information from a study of others.

B．He conducted the experiments on his own.

C．His graduate student, Brittany Trang, told him.

D．Chemists at the University of Alberta told him.

3. What can we learn about Brittany Trang’s experiment?

A．She tried the method from Dichtel but didn’t succeed at first.

B．She pulled apart PFAS with her own idea at her first attempt.

C．She developed a more effective method to break down PFAS.

D．She thought Dichtel’s idea was too simple, so she didn’t try it.

4. What do scientists advocate to the public?

A．Addressing the effects of PFAS on human health and environment.

B．Reducing the amount of PFAS being released into the environment.

C．Finding more effective ways to destroy PFAS in and outside the lab.

D．Stopping the use of PFAS in everyday life to avoid health problems.

3 . Would you take a trip if you couldn’t use your cellphone? A new tour company called Off the Grid is asking travellers to put their cellphones away and not even use them for photos. The company founder, Zach Beattie, is developing his business, using money he saved from a tech job at a mapping company. He’s hired guides for every trip but will help lead the first few himself.

The first trip is to Lisbon, Portugal, in July. It takes 7 to 10 days, with small groups of up to 16 people. Prices range from $1,500 to $1,650, including accommodations, meals and ground transportation. The plan includes at least three excursions (远足) and two social events, with an emphasis on unique experiences over bucket-list sightseeing. The tour also includes surfing lessons, yoga on the beach, a day of sailing and dinner with a local family.

“When you’re somewhere new, there’s a lot to see and a lot of cool and interesting people to meet,” Beattie said. “Your phone can distract (使分心) you.” The phone ban won’t be enforced quite as strictly as it seems at first glance. “We want it to be voluntary,” he said. “We’re not collecting phones and throwing them in a locked trunk. It’s held by you, but put in your pocket, and you state your intentions for the week, whether that’s checking your social media once or twice a day or a total blackout.”

Tour-goers also get a “dumbphone” without Internet access that’s loaded with numbers for group leaders and other participants, both for emergencies and to promote socializing. Participants may bring regular cameras, but Beattie is hiring a photographer for each tour so there will be plenty of photos to remember the trip. Once the trip is over, participants will have access to those photos for use in social media posts.

1. What can be learned about Zach Beattie?

A．He set up his business at his own expense.

B．He is always guiding every trip personally.

C．He forbids tourists to take along cellphones.

D．He used to earn his living in a tour company.

2. What do we know about the Lisbon trip?

A．The trip features sightseeing.

B．Participants live in homestays.

C．Air ticket is covered in the cost.

D．Tourists experience water sports.

3. What does Zach Beattie expect the participants to do?

A．Lock their phones in a trunk.

B．Post their photos on social media.

C．Free themselves from their phones.

D．Shift their focus onto dumbphones.

4. What can tour-goers do with the dumbphone?

A．Take photos.	B．Access the Internet.
C．Record the trip.	D．Contact group members.

6 . On a tram smoothly pulling into the heart of Luxembourg City, Marck gives a smile and takes a look at the fabric of the seat next to him. For him, the city’s trams are more than just transport. More even than the focus of his job. They are about transforming his country and, perhaps, changing the world.

Marck is the director general of Luxtram, Luxembourg’s modern trams. It first started running services two years ago. Next year, Luxembourg will become the world’s only country to get rid of fares on all its forms of public transport. Luxembourg’s traffic problems come from its army of workers. The population of the capital city almost doubles during the working day, when more than 110,000 people travel in and out.

After three decades when its roads have become so crowded, Luxembourg is going to do something remarkable. Free fares, and a plan to persuade people to switch from cars to trams or trains. Marck, along with many others, is excited to see what happens next. “The fact that this is free means that everyone can use it — young or old, rich or poor,” he said. “Everyone can say to themselves it’s better to leave the car at home. We must continue to improve and extend the network. It must always be comfortable, well-connected, efficient.”

Lydie Polfer, the city’s mayor, says she hopes to reach the point where more than a third of people come into the city using public transport — at the moment, it’s less than one in five. She said, “It’s not practical to ban cars because some people, like the elderly, need them. But everyone has to be aware that he or she can do something to improve the situation. There is an expression in German — you are not in the traffic jam — you are the traffic jam, and that is true. I think that making it free will be the biggest arguments for people to use public transport. ”

1. Why does Marck think the city’s trams are more than just transport?

A．The trams are his goal that he strives for.

B．There are more means of transportation than trams.

C．City’s trams bring more changes beyond transport.

D．The trams are the heart of Luxembourg City transport system.

2. What does paragraph 2 mainly talk about?

A．The cause of the traffic problems.	B．The means of public transport.
C．The development of running services.	D．The increase of working population.

3. What concerns people most when using the public transport?

A．The convenience.

B．The fare.

C．The comfort.

D．The efficiency.

4. What can be inferred from what Lydie Polfer said?

A．The elderly needn’t use public transport.

B．It’s possible to persuade most people to use the trams.

C．Everyone can do his part to improve transport situation.

D．Those who don’t take public transport cause traffic jams.

8 . Joao Carlos Martins is a famous pianist and conductor. However, his career has been ________ and his life has taken him in many different ________.

As a teenager Martins began to perform in concerts. But in his late twenties, he had to ________ after badly breaking his arm. It was really a terrible time. He couldn’t look at a piano or ________ listen to music. ________, he decided to become the manager of a boxer, who won the world championship later. This ________ Martins to take up the piano and practise much harder. Six years later, he gave his first concert at the Carnegie Hall, which was the most ________ moment of his life. He performed in concerts for years before he had to quit because of the unbearable ________ in his hands caused by too much ________.

Martins, in his forties, became a politician. However, he couldn’t stand this ________, so once again, he went back to the piano. All was going well until something unexpected ________ while leaving a concert. He ________ a serious brain injury and lost all the movement in his right hand. Again, with great ________ he played just with his left hand. Years later he lost the use of the left hand and ________ himself a conductor. Now, in his late seventies, Martins is still taking ________ to work and has conducted over a thousand concerts.

1.

A．smooth

B．tough

C．flexible

D．interesting

2.

A．cultures

B．forms

C．directions

D．levels

3.

A．give up

B．set out

C．turn up

D．hold out

4.

A．still

B．just

C．ever

D．even

5.

A．Generally

B．Ultimately

C．Occasionally

D．Naturally

6.

A．forced

B．promised

C．motivated

D．forbade

7.

A．realistic

B．emotiona1

C．struggling

D．striking

8.

A．pain

B．cuts

C．tension

D．sensitivities

9.

A．conducting

B．playing

C．instruction

D．competition

10.

A．career

B．popularity

C．condition

D．behavior

11.

A．existed

B．remained

C．occurred

D．continued

12.

A．found

B．suffered

C．cured

D．nursed

13.

A．patience

B．care

C．pleasure

D．determination

14.

A．fancied

B．considered

C．made

D．chose

15.

A．measures

B．chances

C．courage

D．trouble

9 . How Did You Get Five Fingers?

Your arms and toes began as tiny buds that sprouted from your sides when you were just a four-week-old embryo (胚胎). By six weeks, these limb buds had grown longer and five rods of cartilage 软骨) had appeared in their flattened tips. By week seven, the cells between the rods had died away, forming five small fingers or toes from once-solid masses of flesh.

Now, a team of scientists led by James Sharpe from the Centre for Genomic Regulation in Barcelona has discovered that these events are carefully orchestrated by three molecules. They mark out zones in the embryonic hand where fingers will grow, and the spaces in between that are destined to die. Without such molecules, pianos and keyboards wouldn’t exist, and jazz hands would be jazz palms.

These three molecules work in a way first envisioned by Alan Turing, a legendary English mathematician and code-breaker. Back in 1952, Turing proposed a simple mathematical model in which two molecules could create patterns by spreading through tissues and interacting with each other. For example, the first molecule might activate the second, while the second blocks the first. Neither receives any guidance about where to go; through their dance, they spontaneously organize themselves into spots or stripes.

Since then, many scientists have found that these Turing mechanisms exist. They’re responsible for a cheetah’s spots and a zebrafish’s stripes. For 30 years, people have also suggested that they could sculpt our hands and feet, but no one had found the exact molecules involved.

Sharpe knew that these molecules would need to show a striped pattern. Sox9 seemed like the most promising candidate. It is activated in a striped pattern from a very early stage of development. By comparing cells where Sox9 is active or inactive, Jelena Raspopovic and Luciano Marcon found two other groups of genes—Bmp and Wnt—also formed striped patterns. Bmp rises and falls in step with Sox9 and both are active in the digits. Wnt is out of phase; it’s active in the gaps. The three molecules also affect each other: Bmp activates Sox9 while Wnt blocks it; and Sox9 blocks both of its partners. It looked like these were the molecules the team was searching for not a pair, as Turing suggested, but a trinity. To confirm this, they created a simulation of a growing limb bud and showed that Sox9, Bmp and Wnt could organize themselves into a pattern of five stripes, by activating and blocking each other.

There’s still a lot to discover, though. For example, I’ve used Bmp and Wnt as shorthands here—in reality, each represents a class of several molecules, and the team still needs to work out which specific member is part of the Turing’s proposal.

1. The underlined sentence in the second paragraph means that ________.

A．some certain molecules are necessary for the growth of human fingers

B．the development of embryos is dependent on some certain molecules

C．without some certain molecules, music won’t exist in this world

D．the molecules work in a way that Alan Turing once offered

2. What can we learn from the example given in the third paragraph?

A．Molecules interact by following a strict mathematical model.

B．Molecules have a strong will to form patterns in nature.

C．The formation of patterns in nature may be dominated by molecules.

D．Alan Turing was able to track down the movement of molecules.

3. What is “Sox9” according to the passage?

A．A protein that determines humans’ development in childhood.

B．A gene especially important for the development of our limbs.

C．A striped pattern that always interacts with Bmp and Wnt.

D．A simulation of growing limbs that activate and block each other.

4. Which of the following statements is TRUE according to the passage?

A．How human limbs are developed may well be similar to how animal spots are shaped.

B．The way Sox9 interacts with Bmp and Wnt is still a mystery that needs further studying.

C．Sox9 can activate both Bmp and Wnt to form our limbs, according to scientific research.

D．Sox9, Bmp and Wnt are three specific molecules that determine the growth of fingers.