2 . Deveza’s mother was on the waiting list for a kidney transplant (肾移植). Deveza wanted to donate one of her own kidneys, but she was turned down because she might develop the same health problems as her mother in later life.

Deveza came up with a different plan. In 2017, she started the world’s first paired exchange of different organs between living donors, exchanging half her liver (肝) for someone else’s kidney. A case study of the organ exchange has now been published. And the surgeons who were involved are calling for more exchanges like this. “You can imagine the enormous impact for mixed organ extended chains,” says John Roberts, a surgeon at University of California, San Francisco.

Most organ transplants come from people who have died, but there are never enough organs. As most people can manage with just one of their kidneys, people with kidney failure are increasingly receiving donated organs from relatives or friends. If someone wants to donate but their immune (免疫的) system is unsuited, doctors may be able to find pairs of would-be donors who can each give a kidney to the other’s relative.

When Deveza was looking into such chains, she came across research describing the idea of trading a kidney with the only other organ generally taken from a living donor—the liver. She suggested the idea to many hospitals before she finally contacted Roberts, who saw the idea’s potential.

Deveza was assessed to be in good enough health to donate part of her liver. It then took 18 months to find Annie Simmons, in Idaho, whose liver was unsuitable to use as a transplant for her sister with severe liver disease. They drew up a plan: Simmons would donate a kidney to Deveza’s mother, and in return, Deveza would give half her liver to Simmons’ sister. The hospital gave the go-ahead and the four operations took place on the same day successfully.

The team hopes that the ground-breaking case will inspire more people to consider doing the same. Roberts says that direct exchanges involving two donors could enable up to thirty extra living donor liver transplants a year—a ten per cent increase.

1. What did Deveza do to save her mother?

A．Carrying out a case study.

B．Calling for kidney donations.

C．Launching a medical experiment.

D．Trading half her liver for a kidney.

2. What does Paragraph 3 mainly talk about?

A．Patients’ hopelessness to survive.

B．Several sources of organ donation.

C．Current situation of organ transplants.

D．Doctors’ efforts to improve organ transplants.

3. What can be inferred about the organ exchange between Deveza and Simmons?

A．It discouraged organ donation.

B．It brought two families together.

C．It met with widespread approval.

D．It produced a desirable outcome.

4. What is the best title for the text?

A．My Liver, Your Kidney

B．Mother’s Love, Our Happiness

C．Organ Transplant: Blessing for Patients

D．Organ Exchange: Major Medical Advances

6 . A new study suggests that some homemade soups — made of chicken, beef or vegetables — might help fight malaria.

Jake Baum of the Imperial College London led the research. He asked children at a London school to bring in homemade clear soups that their families would make to treat a fever. The soups were then exposed to the parasite (寄生虫) that creates 99.7 percent of malaria cases in Africa, the World Health Organization explained.

Of the 56 soups tested, five were more than 50 percent effective in containing the growth of the parasite. Two were as effective as one drug now used to treat malaria. And four soups were more than 50 percent effective at preventing parasites from aging to the point that they could infect mosquitoes that spread the disease. Baum also noted that it was unclear which foods made the soups effective against malaria.

The soups came from families from different ethnic histories, including Europe, North Africa and the Middle East. They had several main ingredients, including chicken, beef and green vegetables. Baum said the vegetarian soups showed similar results to the soups with meat.

Baum said his aim was in part to show children that scientific research can turn a herbal (草本的) cure into a man-made medicine. He noted the research of Dr. Tu Youyou from China. In the 1970s, she found that the herb quinhao was an effective antimalarial (抗疟疾的) treatment. The herb has been used in Eastern medicine for two thousand years. Tu’s research led to the man-made drug artemisinin (青蒿素), a drug now widely used to treat malaria.

More and more people are becoming resistant (耐受的) to the drugs that treat the disease, which kills nearly 400,000 people a year. That means scientists will have to “look beyond chemistry” and find new drugs, Baum adds.

1. Why did children at a London school bring in homemade soups?

A．To treat a fever.	B．To have for lunch.
C．To compete with others.	D．To take part in an experiment.

2. What do we know about the research led by Jake Baum?

A．What in the soups works is still unknown.

B．Most soups are effective in killing the parasite.

C．Half of the soups can stop mosquitoes from spreading malaria.

D．The vegetarian soups and the soups with meat have different effects.

3. Why does Baum take Dr. Tu Youyou as an example?

A．To emphasize her great achievement in treating malaria.

B．To stress the importance of quinhao in treating malaria.

C．To note a herbal cure can come into a man-made medicine.

D．To show quinhao has been discovered for a long time.

4. What is scientists’ task next?

A．To expand their studies for new medicines.

B．To collect more soups for scientific study.

C．To research into the ingredients of the soups.

D．To find out why malaria exists in many countries.

8 . As we know, mental health is in a worse situation among young people globally.     1     This not only lowers quality of life, but has a negative impact on a teenager’s growth. To get at the root causes of this decline, a group of scientists conducted a study and found the combination of high screen time and low “green time” greatly affects mental well-being. Children nowadays spend more time than ever in front of electronic devices.

The average daily screen time for 8-to-18-year-olds was 7.5 hours in the U. S. ten years ago. As the study states, “This greatly goes above guidelines of 2 hours per day.” Now the condition is worse by the fact that so many schools are using technology to teach classes. Indeed some screen time can promote connections and enable tasks to be done more efficiently.     2     In addition to troubling nerve stimulation, too much screen time takes the place of important protective behaviors for mental health such as physical activity, getting adequate sleep and academic activities.

The study authors suggest that green time could act as a cure for screen time, essentially balancing its negative effects.     3     The attention systems can be restored in natural environment when they are worn out, because they employ involuntary attention there, which is not tiring or effortful.

    4     The great nature could potentially function as a psychological well-being promotion intervention (干预) for children and teenagers in a high-tech era. This knowledge could be a guide to public health departments that are struggling to restore happiness and cheer in countless anxious teenagers.     5    

A．Teenagers urgently need more green time.

B．Screen-based technology makes kids less attentive.

C．The frequency of depression and anxiety is increasing.

D．There are many more ways, nevertheless , in which it is harmful.

E．It suggests more outdoor projects like building parks could be fundamental.

F．Paying constant directed attention to screens can raise directed attention tiredness.

G．This study highlights that nature may currently be a potential public health resource.

9 . The vaccine (疫苗) news continues to seem very encouraging. Britain started its mass vaccination effort and the U.S. isn’t far behind.

But there is still one dark cloud hanging over the vaccines that many people don’t yet understand.

The vaccines will be much less effective at preventing death and illness in 2021 if they are introduced into a population where the coronavirus is still severe—as is now the case in the U.S.

A vaccine is like a fire hose (消防龙头). A vaccine that’s 95 percent effective, as Moderna’s and Pfizer’s versions appear to be, is a powerful fire hose. But the size of a fire is still a bigger determinant of how much destruction occurs.

At the current level of infection in the U.S. (about 200,000 confirmed new infections per day), a vaccine that is 95 percent effective—distributed at the expected pace—would still leave a terrible toll (伤亡人数) in the six months after it was introduced. Almost 10 million or so Americans would catch the virus, and more than 160,000 would die.

This is far worse than the toll in a different situation where the vaccine was only 50 percent effective but the U.S. had reduced the infection rate to its level in early September (about 35,000 new daily cases). In that case, the death toll in the next six months would be kept to about 60,000.

It’s worth pausing for a moment on this comparison. If the U.S. had maintained its infection rate from September and Moderna and Pfizer had announced this fall that their vaccines were only 50 percent effective, a lot of people would have panicked.

But the reality we have is actually worse.

How could this be? No vaccine can get rid of a pandemic immediately, just as .no fire hose can put out a forest fire. While the vaccine is being distributed, the virus continues to do damage.

There is one positive way to look at this: Measures that reduce the virus’s spread—like mask-wearing, social distancing and rapid-result testing—can still have great consequences. They can save more than 100,000 lives in coming months.

1. How does the author mainly present his argument?

A．By giving definitions.	B．By categorizing facts.
C．By drawing comparisons.	D．By appealing to emotions.

2. Which does the author think is a better way to save lives?

A．Improving the effectiveness of the vaccines.

B．Producing a greater variety of vaccines.

C．Looking at the situation in a positive way.

D．Wearing masks and practicing social distancing.

3. What does paragraph 6 tell us?

A．The vaccines are less effective than expected.

B．The US have controlled the spread of the coronavirus.

C．The death toll in the next six months will be about 60,000.

D．Fewer people will die if the infection rate is lower.

4. What can we infer from the text?

A．The vaccine is the hope of wiping out the pandemic.

B．The public are optimistic about the effects of the vaccine.

C．The public are concerned about the high infection rate.

D．The distribution of vaccine will end the pandemic quickly.

10 . Imagine going to the doctor to get treatment for a terrible fever.     1     The robot detects (检测) the cause of your fever, travels to the appropriate system and provides medication directly to the infected area.

    2     They’re called nanorobots (纳米机器人) and engineering teams around the world are working to design robots that will eventually be used to treat everything from fever to cancer.

In recent years researchers have been building nanorobots out of a familiar material—the same stuff that makes human life possible.     3     DNA is literally all around (and in) you —you just can’t see it. If you were to look inside almost any cell inside any living creature, you would find DNA.

This might sound surprising—especially since these nanorobots don’t need batteries or any power source. Instead, they work by using the natural structure of DNA. These nanorobots “crawl” on DNA. Sometimes researchers refer to these things as DNA “spiders”.     4     A nanorobot could, perhaps, destroy just a cancerous cell, for example, but leave healthy cells alone.

    5     But the future is bright for DNA-built nanorobots. One day, perhaps DNA-made machines will swim around in the human body, delivering medicine to diseased cells or helping doctors diagnose problems. Or maybe they’ll help build the smallest computers the world has ever seen.

A．These nanorobots are made of DNA.

B．Nanorobots made from DNA aren’t useful yet.

C．In other words, the DNA nanorobot destroys the track as it goes.

D．This description will give you a simple picture of the legs of a DNA nanorobot.

E．Being able to make such a tiny thing move in a certain way might be useful for health.

F．Instead of giving you a pill or a shot, the doctor puts a tiny robot into your bloodstream.

G．In fact, we’re not that far off from seeing devices like this actually used in medical procedures.