1 . Hazel Mayfield usually cooks the Thanksgiving meal for her extended family in Houston, Texas. She usually welcomes friends and neighbors who are eager to taste her fried turkey, green bean casserole, candied yams, homemade cornbread dressing, and dirty rice-just a few of her signature dishes. Known as Sugar Mama, because her grandchildren think she’s so sweet, the 91-year-old typically likes to do her own shopping for the ingredients to make her special dishes.

“My mother is the head cook of the family,” said Panulette Mouton, Mayfield’s daughter. “Because of her reputation, you know, there’re people in and out all day and every family comes through. They want to get some of Sugar Mama’s cooking, and some of them would like to learn from her how to cook the food.”

But Mayfield hasn’t been to the grocery store since March. And there is little about Thanksgiving in 2020 that’s usual. Because of Covid-19, the deadly virus that has killed millions in the U.S. and spoiled life around the world, everything is different. Since limiting close face-to-face contact with others is the best way to reduce its spread, hundreds of thousands of American families have re-imagined the holiday with virtual celebrations and canceled or delayed travel plans. There can only be small gatherings with people in their households in response to COVID-19.

This year, Mayfield’s family members, without exception, are lamenting the absence of a big gathering. They’ve explained to their young children and grandchildren why this year’s Thanksgiving is different. Mayfield’s youngest daughter, Michelle Sanders, says it’s tough to help her grandchildren understand why they can’t see some of their other family members and why they have to stay at home, celebrating Thanksgiving all by themselves.

“It’s really hard, trying to explain to them,” Sanders said. “When-you’re talking to them and they want to come over, you have to tell them no. They really don’t know how to be careful.” Sanders added, “And, they don’t understand that, being three, four, and six, you know they don’t really understand that. So, it’s...it’s really, really hard, and heartbreaking.”

1. According to the passage, Hazel Mayfield is ________.

A．helpful and kind-hearted	B．stubborn and enthusiastic
C．talented and instructive	D．grateful and sensitive

2. The underlined word in paragraph 4 can be best replaced by ________.

A．fascinated by	B．upset about
C．ignorant of	D．embarrassed at

3. What can we infer from what Sanders said in the last paragraph?

A．Children are too young to understand the situation.

B．Children are always careless on Thanksgiving Day.

C．It’s tough to help children overcome their problems.

D．Adults should show patience when talking with kids.

4. What do we know about the effect of COVID-19 according to the passage?

A．People are cutting down holiday celebration expenses.

B．People are trying hard to get together to have more fun.

C．People have to make changes in their lifestyle to stay safe.

D．People have put more emphasis on the traditional customs.

2 . Round and Round They Go

Space is becoming more crowded. On December 3, a Falcon 9 rocket made by Space X thundered into the sky. On board were 64 small satellites, more than any American company had launched before in one go. They have a variety of uses, from space-based- radar to the monitoring of radio-frequency- emissions.

These objects are part of the latest breed of low-Earth-orbit (LEO) satellites. This launch is just taste of what is planned. Space X and One Web, a communications firm, plan to launch satellites in their thousands, not hundreds. The pair are set to double the total number of satellites in orbit by 2027.

That promises to change things dramatically on Earth. LEO satellites can bring internet connectivity to places where it is still unavailable or unaffordable. This will also be a lasting source of new demand for the space economy. Morgan Stanley, a bank, projects that the space industry will grow from $350 billion in 2016 to more than $1. I trillion by 2040. New internet satellites will account for a half this increase.

For that to happen, however, three worries must be overcome. Debris(碎片)is the most familiar concern. As long ago as 1978, Donald Kessler, a scientist at NASA, proposed situation in which, when enough satellites were packed into low-Earth orbits, any collision could cause a chain reaction which would eventually destroy all space craft in its orbital plane(平面). The syndrome which bears Mr. Kessler's name weighs heavily on the minds of executives at the new satellite firms. Debris could cause entire tracts(广阔的一片) of space to be unusable for decades.

Solutions exist. One is to grab malfunction satellites and pull them down into Earth's atmosphere. Another is to monitor space more intensively for debris; a US Air Force program me called Space Fence is due to start in 2019. But technology is only part of the answer. Rules are needed to govern the safe disposal(清除) of old satellites from low-Earth orbit. The United States' Federal Communications Commission is revising its regulations with this in mind. Other countries should follow suit.

Cyber-security is a second, long-standing worry. Hackers could take control of a satellite and seal intellectual property, redirect data flows or cause a collision. The satellite industry has been slow to respond to such concerns. But as more of the world's population comes to rely on the infrastructure of space for access to the internet, the need for action intensifies.

The third issue follows from the first two. If a simple mistake or a cyber-attack can cause a chain reaction which wipes out hundreds of billions of dollars of investment, who is liable? Underwriters(保险商) are studying the plans of firms that wish to operate large numbers of satellites. But there is a long way to go before the risks are well understood, let alone priced.

As space becomes more commercialized mind-bending prospects open up: packages moved across the planet in minutes by rocket rather than by plane, equipment sent to other small planets, passengers launched into orbit and beyond. All that and more may come, one day. But such activities would raise the same questions as LEO satellites do. They must be answered before the space economy can truly develop.

1. What can we learn about LEO satellites from the passage?

A．They are supposed to limit the space economy.

B．They are expected to increase in large numbers.

C．They are designed to move beyond the Earth as far as possible.

D．They are mainly intended to bring internet connectivity to remote areas.

2. To deal with debris in space, the author suggests________.

A．depending entirely on the modern technology

B．monitoring the movement of spaceships carefully

C．strengthening rules to remove old satellites safely

D．destroying all the satellites with problems instantly

3. What does the underlined word “intensify” in Paragraph 4 probably mean?

A．Measure.

B．Increase.

C．Spread.

D．Repeat.

4. Which of the following can be classified as the third worry?

A．Lack of satellite regulations.

B．Loss of intellectual property.

C．Crisis of confidence in the field.

D．Slow response of satellite industry.

5. What is the author's attitude toward the launch of LEO satellites?

A．It should be further confirmed for its ownership.

B．It should be continued because of its advantages.

C．It should be done carefully to avoid potential risks.

D．It should be stopped in face of the space economy.

3 . Every year more people recognize that it is wrong to kill wildlife for “sport”. Progress in this direction is slow because shooting is not a sport for watching, and only those few who take par realize the cruelty and destruction.

The number of gunners, however, grows rapidly. Children too young to develop proper judgments through independent thought are led a long way away by their gunning parents. They are subjected to advertisements of gun producers who describe shooting as good for their health and gun-carrying as a way of putting redder blood in the veins（血管）. They are persuaded by gunner magazines with stories honoring the chase and the kill. In school they view motion pictures which are supposedly meant to teach them how to deal with arms safely but which are actually designed to stimulate（刺激）a desire to own a gun.

Wildlife is disappearing because of shooting and because of the loss of wildland habitat Habitatloss will continue with our increasing population, but can we slow the loss of wildlife caused by shooting? There doesn't seem to be any chance if the serious condition of our birds is not improved. Wildlife belongs to everyone and not to the gunners alone. Although most people do not shoot, they seem to forgive shooting for sport because they know little or nothing about it. The only answer, then, is to bring the truth about sport shooting to the great majority of people.

Now, it is time to realize that animals have the same right to life as we do and that there is nothing fair or right about a person with a gun shooting the harmless and beautiful creatures. The gunners like to describe what they do as character-building, but we know that to wound an animal and watch it go through the agony of mortality can make nobody happy. If, as they would have you believe, gun-carrying and killing improve human character, then perhaps we should encourage war.

1. According to the text, most people do not seem to be against hunting because      .

A．they have little knowledge of it.

B．it helps to build human character.

C．it is too costly to stop killing wildlife.

D．they want to keep wildlife under control.

2. The underlined word “agony” in the last paragraph probably means      .

A．difficulty.

B．tress.

C．pain.

D．sadness.

3. According to the text, the films children watch at school actually      .

A．teach them how to deal with guns safely.

B．praise hunting as character building.

C．describe hunting as a physical exercise.

D．encourage them to have guns of their own.

4. By saying “perhaps we should encourage war”, the writer intends to tell us that      .

A．Hunting to build human character makes no sense.

B．War in the best way to improve human character.

C．We are on the edge of war against gunners.

D．Protecting wildlife from gunners is extremely difficult.

4 . If your in-box is currently reporting unread messages in the hundreds or thousands, you might have a hard time believing the news: e-mail is on the decline.

At first thought, that might seem to be the case. The incoming generation, after all, doesn’t do e-mail. Oh, they might have an account. They use it only as we would use a fax machine: as a means to communicate with old-school folks like their parents or to fulfill the sign-up requirements of Web sites. They rarely check it, though.

Today’s instant electronic memos — such as texting and Facebook and Twitter messages — are more direct, more concentrated, more efficient. They go without the salutation (称呼语) and the signoff (签收); we already know the “to” and “from.” Many corporations are moving to messaging networks for exactly that reason: more signal, less noise and less time. This trend is further evidence that store-and-forward systems such as e-mail and voicemail are outdated. Instead of my leaving you a lengthy message that you pick up later, I can now send you an easily-read message that you can read — and respond to — on the go.

The coming of the mobile era is responsible for the decline of e-mail. Instant written messages bring great convince to people. They can deal with them at about any time: before a movie, in a taxi, waiting for lunch. And because these messages are very brief, they’re suitable for smart phone typing.

Does this mean e-mail is on its way to the dustbin of digital history? Not necessarily. E-mail still has certain advantages. On the other hand, tweets and texts feel ephemeral — you read them, then they’re gone, into an endless string, e-mail still feels like something you have and that you can file, search and return to later. It’s easy to imagine that it will continue to feel more appropriate for formal communications: agreements, important news, longer explanations.

So, e-mail won’t go away completely. Remember, we’ve been through a transition (过度) like this not so long ago: when e-mail was on the rise, people said that postal mail was dead. That’s not how it works. Postal mail found its smaller market, and so will e-mail. New technology rarely replaces old one completely; it just adds new alternatives.

1. What would the incoming generation like to do with their e-mail accounts?

A．Check bank accounts.	B．Send long messages.
C．Fill in some forms.	D．Communicate with their colleagues.

2. Which of the following is mainly discussed in paragraphs 3 and 4?

A．The possible reasons behind the decline of e-mail

B．The likes and dislikes of the young generation

C．The rapid development of e-communication channels

D．Evidence about the uncertain future of easily-consumed messages

3. What does the underlined word “ephemeral” in paragraph 5 mean?

A．Automatically-sending.	B．Randomly-written.
C．Hardly- recognized.	D．Shortly-appearing.

4. According to the passage, which of the following statements is true?

A．It’s too early to determine the decline of e-mail.

B．E-mail has reasons to exist with its own advantages.

C．E-mail, just like postal mail has come to its end.

D．We should feel sorry for the decline of e-mail.

5 . Copper surfaces kill microbes (微生物)that come into contact with them in a matter of hours. A new technique makes the familiar metal even deadlier.

Bacteria “are becoming more aggressive and resistant to medicines; it's the same thing for viruses/' says Ravi Rahimi, a materials engineer. "There is a lot of interest in how to create surfaces that actually, on contact with the bacterium or the virus, immediately lull the pathogen (病原体)" because this "thwarts” the spread of that pathogen into the environment."

Copper is a good candidate, for such surfaces: humans have been taking advantage of its bacteria-killing properties for at least 8,000 years. People in some Bronze Age civilizations let their drinking water rest in copper vessels to avoid disease, says Michael Schmidt, a microbiologist, who was not involved in the new research. Copper's germ-destroying power, he explains, comes from its ability to conduct electricity. When a microbe touches a metal surface, the substance carries electrons always from the microbe's cellular membrane (细胞膜).This reaction sets off a chemical process that finally forces open the organism's pores (毛孔)and destroys it. .

To enhance the process, Rahimi's team hit a copper sample with laser light for a milliseconds, thereby creating nanoscale pores in the fiat metal and increasing its surface area. Schmidt says the added vertical structures “increased the amount of 'square fbotage⁵ available to kill microbes? The rough surface also made the copper cling (附着于)more strongly to water - and thus to any bacteria within it.

The researchers tested this newly rough surface by placing several bacterial species on both flat and laser-treated pieces of copper. As soon as the cells hit the metal, their membranes began to suffer damage; that surface completely destroyed the bacteria, in some cases much more quickly than the untreated one. The surface killed some viruses immediately on contact and took from 40 minutes to two hours to wipe out a full colony, depending on the species and concentration.

The laser treatment could also work with other metals, including titanium, which is often used for surgical implants, Rahimi says. He points out that all types of metals display some antimicrobial properties, although titanium, which has little conductivity, kills germs much more slowly than highly conductive ones such as copper.

1. What does the underlined word “thwarts” in Paragraph 2 most probably mean?

A．Predicts.

B．Tracks.

C．Reveals.

D．Contains.

2. What is the focus of the third paragraph?

A．The measures to use copper.

B．How microbes are destroyed.

C．Why electrons are carries away.

D．The undiscovered power of copper.

3. What is at the core of the new technology?

A．The speed of laser light.

B．Bacteria's reaction to water.

C．Making the metal surface unsmooth.

D．Reshaping the function of cellular membrane.

4. What is the purpose of the text?

A．To present the application of laser-treated copper.

B．To seek a cure for infectious diseases.

C．To show which metals are more bacteria-resistrant.

D．To introduce a new metal for surgical implants.

6 . Invented by French teenager Louis Braille in 1824, Braille has enabled blind kids worldwide to learn to read and write. However, the system of raised dots, representing letters and numbers, can be hard for younger students to learn. As a result, parents and educators are increasingly avoiding this system, which is taught using special textbooks, in favor of online learning programs. Now，Denmark's LEGO Foundation hopes to change the trend with the help of braille bricks（ 盲文积木）.

The braille bricks are similar to original building blocks. However, the bricks with numbers and letters printed on the bottom allowed blind and sighted players to build together. Though the bricks can be stacked together to form a crossword game or attached to one another to form words, they are unlike the regular ones. Therefore, the company recommends placing the bricks side-by-side. Each set of about 250 pieces includes letters A-Z, the numbers 0 -9, as well as basic symbols like the “plus” and “minus” signs. Special pieces are also included so kids can play word and math games.

Blind kids have dreams about their future just as sighted children. They have the same desire to explore the world and socialize through play. In the Foundation, children can learn best through play and, in turn, develop their skills, such as creativity and communication. With this project, the foundation is bringing a playful and inclusive approach to learning braille to children.

Kids are not the only ones benefiting from LEGO's invention this year. It can benefit adults as well. For those not into gaming, there is “Lego Art”. The art enables adults to create pop art “posters” by arranging these bricks on a canvas（画布）. The offering includes Andy W arhol's Marilyn Monroe，Marvel Studio's Iron Man, and The Beatles. Each set comes with the appropriate music, interviews, and background information, providing fans with an unforgettable experience as they create their masterpieces.

1. Why do educators avoid teaching in braille?

A．Braille becomes out of date in reality.

B．Braille is difficult for blind kids to master.

C．They are not good at it at all.

D．The special textbooks are expensive.

2. What does the underlined word “stacked" in Paragraph 2 mean?

A．Piled.	B．Crashed.
C．Pushed.	D．Crossed. .

3. What are blind kids expected to do in the LEGO Foundation?

A．Pursue their hobbies.	B．Form their habits.
C．Develop their skills.	D．Play for fun.

4. How can adults benefit from the braille bricks?

A．They can play games together with their kids.

B．They can get more information from those bricks.

C．They can create some artworks based on the offering.

D．They can impress themselves with a wonderful scene.

7 . Great Barrier Reef Choking on Pollutants

Attempts to protect the Great Barrier Reef are failing. A report released Monday by the government in Australia says water quality in the Great Barrier Reef is far below what it should be. It showed that pollution have decreased, but not enough to reach environmental targets.

Sediment (沉淀物) and chemicals can weaken coral, hurting its ability to feed and grow. Coral are live animals that take root in the ocean floor, but they are not plants. Reefs are the hard skeletons (骨架) left at the bottom of the sea by small marine creatures called polyps (珊瑚虫). The polyps then form the larger structure of a reef. Corals also are some of the most diverse ecosystems on the entire planet. They can make a home for invertebrates, crustaceans, fish, and sea snakes.

Steve Miles is Queensland’s environment minister. He says the research shows the Reef needs more protection. “Over that five-year period, we did see some progress towards our targets. Sediment is down 12 percent and pesticides (杀虫剂) loads are down 30 percent. But what is most disturbing is that these results are far from our targets. Progress towards these targets flat-lined in the period 2013-2014. If one of my kids came home with a report card like this, I would be a bit disappointed. There is more bad news here than good news. ” said Steve Miles.

The report also found that fewer than one-third of Queensland’s sugar plantations used techniques to reduce the use of pesticides. Only 28 percent of land managers managed their land properly. They had reduced harmful water run off to protect the health of the Reef. The official target is a 90 percent reduction in pesticide use within three years.

Scientists at the University of Queensland and the Australian Institute of Marine Sciences published their findings Wednesday, July 18 in the journal Science Advances. It found between 1992 and 2010, the recovery rate dropped by an average of 84 percent. But there is hope. The study also found some corals can recover quickly if “acute and chronic stressors” are lessened.

Meanwhile, the Australian government released its updated reef protection plan Friday. It clearly states global temperatures must be stopped from rising in order to save the world’s largest living structure.

1. What does the underlined word “They” in Paragraph 2 refer to?

A．Diverse ecosystems.	B．Sediment and chemicals.
C．Reefs and corals.	D．Small sea creatures.

2. What can be learned from what Steve Miles said?

A．He is satisfied with the protection of the Reef.

B．He thinks that the Reef needs more protection.

C．He feels angry with what his children did.

D．He is very happy about the Reef progress protection.

3. What does the underlined word “flat-lined” mean in Paragraph 3?

A．Not increase significantly.	B．Disappear.
C．Speed up.	D．Miss the chance.

4. The report found the majority of land managers in Queensland   ________.

A．were tough to deal with	B．failed to manage their land properly
C．reduced the amount of harmful water	D．were eager to quit pesticide soon

5. Where is the passage most likely to have been taken from?

A．A news report.	B．A science fiction.
C．A book review.	D．A guide book.

8 . NASA has observed a strange effect of human spaceflight: astronauts' blood going backwards and clotting (凝固).The observations could have serious effects on plans to send astronauts to Mars and to allow tourism in space.

An unnamed astronaut on the International Space Station(ISS) was carrying out a scan on his body - guided by experts on the ground. Similar test before the astronaut went to space came back normal, but the scan taken in space revealed a clot of blood,appallingNASA doctors. "We were not expecting this. This has never been reported before,^”said NASA scientist Karina Marshall-Goebel.

The astronaut didn't have any clot-related symptoms, but was given blood-thinning medication for the rest of his time in orbit to prevent more clots forming.

NASA researchers then observed the jugular veins of 11 astronauts on the ISS, and in five of those 11 astronauts, blood flow in jugular vein had stopped. The jugular vein is one of the most important parts of the body, which runs between the heart and the head, draining (使流走) oxygenated blood from the brain. This “draining" process is an essential way to reduce pressure in the brain. Blood that doesn't move normally through the body is a major concern because it can lead to clotting, which can cause more serious problems like damage to the lungs.

The blood in the jugular vein also began moving in the opposite direction (from the heart towards the head) for two astronauts. NASA scientists described this as “extremely abnormal” : and said that the blood may have switched directions due to a blockage. A similar phenomenon has been observed on Earth for patients with tumours (肿瘤)that force blood to find a different route to the heart.

“I think it was probably scary for everybody. But I think the fact that we found this now is really, really good news, because if you know this is a risk factor of spaceflight, it's something that you can monitor and prevent," said Ms Marshall-Goebel.

1. What does the underlined word “appalling” in Paragraph 2 mean?

A．Relaxing

B．Embarrassing

C．Attracting

D．Shocking

2. What can be learned about blood flow in the jugular vein?

A．It seems to clot frequently.

B．It keeps the brain oxygenated.

C．It places great pressure on the brain.

D．It usually runs through the heart to the head.

3. What might NASA scientists do next?

A．Monitor various risk factors of spaceflights.

B．Find ways to deal with astronauts' blood clots.

C．Create an Earth-like environment for astronauts.

D．Explore reasons for the blood changing directions.

4. What's the best title for the text?

A．Astronauts experience faster blood flow in space

B．Astronauts' blocked veins bring medical insight

C．Astronauts' blood flows backwards in space

D．Astronauts are suffering from serious blood diseases

9 . Journalism (新闻业) is a fast-paced industry, requiring reporters to get the facts about newsworthy events and to write about them before a deadline (截止日期). It takes some skills to do this. At the same time, news reporters must follow strict requirements and have a deep understanding of news writing.

Know what you’re going to write about. Newsworthy events can happen anytime and anywhere. So reporters need to develop a good nose for news.

Get all the facts and look at the details. Be sure to look at a story from different angle (角度). Even if you are covering a popular story or topic that others are writing about, look for an angle that will make this one yours.

Check facts to avoid mistakes. Sources may also make mistakes and some may even deceive you. It’s wise to get in touch with other sources. In a shooting incident, for example, getting the facts from the police and from both the criminal (罪犯) and victim isn’t enough. You should also interview other witnesses who may give more information about the incident. Interviewing people and getting a firsthand source on your topic can be valuable.

Start writing the news. When it comes to the body of the article, the main information should be given in the leading statement. It is often a short one, including the basics of what happened, where and when it took place, who was involved and why it’s newsworthy. These details are the main point that informs the reader. Other information about the story follows. This form allows editors to cut off the last paragraphs if there’re space limits.

Check your article for mistakes. If time permits, leave the article for a moment and then read through it again with a fresh eye. Newspaper publications usually have someone check for mistakes but keep in mind that you’re the first line of defense. Grammar mistakes are embarrassing (令人尴尬的), and some mistakes may result in a lawsuit(诉讼).

1. What can we learn about journalism from the first paragraph?

A．It is developing fast.	B．It is very challenging.
C．It is very interesting.	D．It is popular worldwide.

2. What does the underlined word “deceive” in Paragraph 4 mean?

A．Warn.	B．Assist.
C．Interest.	D．Cheat.

3. What should a good news article be like according to Paragraph 5?

A．It begins with a summary.	B．It ends with a happy ending.
C．It has enough smart questions.	D．It gives opinions about the event.

4. How can a reporter avoid getting embarrassed by his news report?

A．By choosing a proper topic.	B．By checking it for grammar mistakes.
C．By filling it with enough details.	D．By removing boring facts from it.

10 . Zhong Zhong and Hua Hua have made medical history as the first cloned primates (灵长目动物),with the efforts of a team of Chinese scientists.

According to the journal Cell , it is a milestone for biomedical research. It could potentially lead to the development of new treatments for human disease. But it also makes ethicists (伦理学者) about where this all might lead. Do Zhong Zhong and Hua Hua suggest the coming of human cloning?

Born in 1996, Dolly the sheep was the first cloned mammal, and was followed by many more, including dogs, rabbits and pigs. But researchers were unable to clone primates because the genes involved didn’t react well to the procedure. Over the years, a handful of research institutions have tried and failed to birth a live monkey clone.

The successful team, at Shanghai’s Chinese Academy of Sciences, used the same basic method that created Dolly but had failed in subsequent(随后的) primate cloning attempts. It’s called somatic（躯体）cell nuclear transfer and involves transferring DNA from adult cells into eggs that have had their own DNA removed. Without the addition of sperm(精子), the eggs are stimulated （刺激）chemically to develop into an embryo that’s a clone of the DNA donor(提供者). The embryo is then placed into a substitue(替代) for gestation（妊娠）.

The researchers modified the approach in two important ways, however. Rather than use adult cells in the DNA transfer, they used fetal (胎儿)cells, which react better to chemical stimuli（刺激）for embryo development, says Mu-ming Poo, director of the academy’s Institute of Neuroscience and a co-autho of the paper. They also fine-tuned the cell transfer process to minimize damage to the eggs

As for creating human clones, Poo says the research shows it can be done, but he and his team have no interest. “Besides many technical dificulties that remain to be overcome, we see no justifiable reason to do human cloning,” says Poo, “nor would the societies around the world permit such an attempt.”

While human cells may be cloned experimentally, for example to research tissue regeneration, the cloning of an entire human is illegal in more than 70 countries, according to the Center for Genetics and Society. U.S. law does not ban it, but over a dozen states do. (Discover 2019J&F,P60.)

1. About   somatic cell nuclear transfer, which of the following statements is true?

A．It needs the combination of sperm and eggs.

B．The eggs keep their own DNA in the process.

C．The embryo has the DNA of the adult donor.

D．The embryo gestates in the eggs donor’s body.

2. What does the underlined word “justifiable” mean in paragraph 6 ?

A．acceptable.

B．incredible.

C．valuable.

D．reliable.

3. Which does not contribute to the success of the primate cloning?

A．The right   donor cells.	B．The fine-tuned transfer process.
C．The united team.	D．The reduced damage to the eggs.

4. Where can this passage be found?

A．Nature Exploration	B．Science   Magazine
C．Medicine World	D．World Wonders