1 . Scientists have been trying to figure out how to alter the genes of humans for many years, and it looks like they’ve finally cracked (破解) the code. But while this may seem like a great step forward in science, some also believe that it’s one step back when it comes to ethics (道德准则). In August, a group of scientists from the USA and South Korea worked together to successfully edit a human embryo (胚胎) and remove a genetic mutation (突变) that would have led to heart disease, reported The Guardian. This was done with the help of CRISPR, a gene-editing tool that allows scientists to “cut and paste” human DNA.
Although this was the first example of an embryo’s genes being changed successfully, the advantages of gene editing have already been tested in living patients. In 2015, a five-month-old girl from the UK was saved after doctors used edited cells to fight off her cancer. As of today, she’s alive and well. And in the USA last year, scientists managed to remove HIV cells from several patients by editing the genes inside their bodies.
Some people hope that in the future, diseases or birth defects could simply be "edited out”. However, others believe this could lead to so-called designer babies, giving parents the option to choose everything from eye color to intelligence. “You could find wealthy parents buying the latest “upgrades” for their children, leading to even greater inequality than we already live with,” Marcy Camovsky, director of the San Francisco Center for Genetics, told BBC News.
In spite of these ethical concerns, experts say it’s not possible to create the “perfect” human being. Despite the progress scientists have made, we don’t understand human genes enough to give all unborn children great brainpower or amazing singing abilities. “Right now, we know nothing about genetic enhancement,” Hank Greely, a director at Stanford University, USA, told The New York Times. “We’re never going to be able to say, honestly, this embryo looks like it would score high on the two-part SAT.”
So it looks like if we want good exam results, or to impress people with our piano skills, we’ll have to stick with the old fashioned method of plain hard work---at least for now.
1. The underlined word “alter” in Paragraph 1 probably means ________.| A．record | B．change | C．remove | D．increase |
| A．A genetic mutation related to heart disease was removed by scientists. |
| B．A newborn baby with cancer was saved by edited cells. |
| C．HIV cells were removed from patients9 bodies. |
| D．Some birth defects were simply edited out. |
| A．They don’t think it is an effective way to fight diseases. |
| B．They are concerned that it could lead to genetic mutations. |
| C．They think it could lead to designer babies and increased inequality. |
| D．They worry that it could make parents abandon children with birth defects. |
| A．Gene editing is regarded as the perfect way to treat birth defects. |
| B．There is still a long way to go to fully understand human genes. |
| C．Gene editing could help enhance human intelligence in the near future. |
| D．Scientists are pessimistic (悲观的) about the future of gene editing. |
2 . The public nowadays has a misunderstanding of forest fires, believing that fires should be kept out of every type of forest. Many of us can recall Smoky the Bear's famous warning: “Remember, only YOU can prevent forest fires”. However, that's not always the case. Under the right conditions, and when conducted safely, fire can create many environmental benefits as well as help prevent larger, uncontrollable wildfires.
After a forest fire, many wildlife species will move into recently burned areas to feed on these newly available foods. Some reptiles and amphibians such as the pine (松树） snake prefer forests frequently burned by fire. As Herbert Stoddard put it, “One of the most harmful things modern man has done to birds has been his attempt to exclude fire from fire-type pine forests. Within a few years most forests choke up with bushes, lose their prairie-like vegetation (草原般植被） and can no longer support birds dependent on periodic burning for their food supply and proper cover.”
If you are asked to picture the forest floor, what do you see? Pine needles, cones, leaves, branches might come to mind-all sources of fuel. If these fuel sources build up without any type of removal, the 'fuel load' can lead to fires catastrophic to forests and people alike. In contrast, prescribed fire can be used by forest professionals every couple of years to keep forest fuels at an appropriate and manageable level. They can also minimize the spread of pest insects and disease and remove unwanted tree and plant species. Plus, they can create and maintain important wildlife habitats rich in grasses and promote the growth of trees, wildflowers and other various plants.
Many organizations and agencies work to promote fire on the landscape when and where appropriate. Smokey Bear even has an updated warning: “Only You can Prevent Wildfires,” as the Forest Service has over the last few decades developed policies and procedures to include prescribed fire as a management tool, as well as continuing their work to prevent and fight wildfires.
1. Why did the author mention Smoky the Bear's warning?| A．To introduce the topic of the passage. |
| B．To clarify a misunderstood concept. |
| C．To show the significance of fire prevention. |
| D．To raise people's awareness of forest protection. |
| A．Forest bushes. |
| B．Fuel sources. |
| C．Pine forests. |
| D．Periodic burning. |
| A．To put out wildfires. |
| B．To keep the forest balance. |
| C．To remove tree and plant species. |
| D．To keep the fuel rich in the forest. |
| A．One Match Can Start A Forest Fire |
| B．Where There Is Smoke There Is A Fire |
| C．Not All Forest Fires Are Created Equal |
| D．Why Not Keep The Forest Fire Burning |
3 . Until now, scientists haven’t been able to study the new rock on the moon.The new samples from Chang’e 5 will change this. They’re from near Mons Rümker, a volcanic mountain where the rock is thought to be much younger-- about 1 billion years old.
There are a lot of reasons scientists are eager to study this younger rock, one of which is that it could help us more precisely date not only the moon, but many rocky planets and other objects.
Here’s how that works: Scientists date lunar rock by using something called a chronology curve（年代学曲线）, says Jollliff, a scientists at Washington University in St. Louis. Basically, they estimate the age of the rock by counting the number of craters（火山口） in the area the rock comes from; those increase as objects strike the rock over time. To make this estimation, scientists need to match the number of craters to a precise age. Right now, they only have data points for lunar rock that is 3 to billion years old. Modern techniques can date the new sample extremely accurately, and once scientists know its precise age, they can add a valuable data point to their chronology curve. The dating system will also help us more accurately estimate the age of all sorts of objects in space, like rocky planets and other moons.
Another reason scientists are keen to study this young volcanic rock is to find out more about how volcanism works on the moon. Jollliff says that it’s unclear why there was volcanic activity on the moon for such a long period of time. Most of the moon; s volcanic activity, he says, is thought to have occurred 3 or 4 billion years ago, when the moon was still pretty young. But since the moon does not have plate structure, which drives volcanism on Earth, it’s unclear what could have caused much later volcanic activity. “That’s something that you can find out of the samples by studying them in the lab,” Jollliff says.
1. What does the underlined word “this” in paragraph 1 refer to?| A．The fact of being unable to study the new rock. |
| B．The new rock from near Mons Rümker. |
| C．One of the reasons to study the moon;s new rock. |
| D．The study of the moon’s younger rock. |
| A．ensure there was volcanic activity on the moon. |
| B．more precisely date only the moon. |
| C．date lunar rock by using a chronology curve. |
| D．explore how volcanism works on the moon. |
| A．Scientistsare keen to study this young volcanic rock. |
| B．Scientists can’t know why volcanic activity exists on the moon. |
| C．The moon’s volcanic activity occurred 3 or 4 billion years ago. |
| D．It’s clear what could have caused much later volcanic activity. |
| A．How scientists study the younger rock. |
| B．Why the research is important. |
| C．Why the younger rock is worth studying. |
| D．What scientists do to study the younger rock. |
4 . Ian McKenna was in third grade when he learned that many kids at his Austin school weren't getting enough to eat at home. He wanted to help, but local volunteer organizations turned him away, saying he was too young. So he decided to find his own solution. For years, he had been gardening with his mother, and they often distributed their extra vegetables to the neighbors. “Why not give the produce to a soup kitchen? Then I thought, I'm good at gardening," says McKenna, now 16. “Why not plant a garden at school, so that kids in need could take food home?"
McKenna persuaded his school to set aside space for a garden; then he asked the community for donations of seeds and equipment. Other students donated their time. Within months, McKenna's garden was producing lettuces, tomatoes, cucumbers and squash for students and their families. Now, seven years later, McKenna's Giving Garden project has expanded to five area schools in addition to his own backyard garden, and he has provided organic produce, enough for 25,000 meals, to Austin families.
For most of his gardening activities, McKenna wears the same T-shirt in different colors, with his personal motto on it: BE A GOOD HUMAN. To him, that means helping in any way you can, no matter what your age. "Even a smile might change someone's life," he says. “It lets them know that they are important. It can make their day."
When COVID-19 hit the U.S., McKenna redoubled his efforts, cooking up to 100 meals to distribute to the hungry on the weekends. When social distancing meant that volunteers couldn't work on community garden plots, he started offering online classes and a gardening hotline so families could grow at home. While gardening is his core focus, McKenna says he is always looking for new ways to help the hungry.
1. What caused Ian's decision to help the kids in his own way?| A．Being rejected by volunteer groups. | B．Being good at gardening. |
| C．A soup kitchen's support. | D．His mother's suggestions. |
| A．It helps students only. | B．It was started with joint efforts. |
| C．It is funded by schools. | D．It earns great profits every year. |
| A．Where there is a will, there is a way. | B．A small gesture makes a difference. |
| C．One good turn deserves another. | D．Love can break all the barriers. |
| A．Ian McKenna, Growing a Food Bank |
| B．Ian Mckenna, an Experienced Gardener |
| C．Giving Garden Project, an Impossible Mission |
| D．Giving Garden Project, a Universal Solution |
5 . Trucker Gerlock traveled hundreds of thousands of miles with his dog, Holly, who came with him on every route—including his last one. While driving near Dallas, Texas, on the job, the 59-year-old Marylander crashed into a concrete column. Gerlock was killed instantly. Looking in the back of the truck, though, rescue drivers found one survivor.
Rescue workers cut the Chesapeake Bay retriever(切萨皮克海湾寻回犬)—practically untouched—out of the back of the truck, where she’d been sleeping. “It’s amazing that anything survived, ”Sandy Nordhoff, friend of Gerlock, told The Kent County News.
Unsure what happened to Holly, Gerlock’s friends from his town of Rock Hall, Maryland, made numerous calls and emails to agencies in order to find out where the dog was. Eventually, they found out she had been staying in Dallas Animal Services shelter and a foster family had taken her in for Thanksgiving. The Rock Hall locals hatched a plan to get her home.
Joe Creighton and Sandy’s husband, Russell Nordhoff, both lifelong friends of Gerlock, volunteered to make the 2, 800-mile trip from Rock Hall to Dallas and back, which took two days each way. The friends borrowed Gerlock’s pickup truck for the road, so Holly would feel more comfortable on the journey home, according to The Kent County News.
Back in Rock Hall, some of Gerlock’s friends adopted Holly. Ever since, the dog has been a town icon(偶像), making an appearance in almost every town parade.
“The outpouring of love shown towards Gerlock and Holly was heartwarming, ”Rock Hall resident Jamie Elburn tells Reader's Digest. “It shows how the companionship of‘man’s best friend’and simple kindness can overcome even the most difficult situation!”
1. What does the underlined part in Paragraph 2 indicate?| A．The trip was extremely tiring. | B．The result was quite satisfying. |
| C．The survivor was very smart. | D．The accident was too serious. |
| A．She was nowhere to be found. | B．She was put in an animal shelter. |
| C．She was sent back home immediately. | D．She was adopted by a foster family. |
| A．It was painstaking. | B．It was full of danger. |
| C．It tumed out to be interesting. | D．It required much experience. |
| A．Sympathetic. | B．Grateful. | C．Shocked. | D．Touched. |
6 . People who have kids live longer than those who remain childless, an academic study has suggested. Researchers believe it is because adults’ immune systems are “refreshed” when kids go to nursery and start picking up infections.
During the course of someone’s life, their immune system can become weaker. But when kids start bringing infections home, their parents’ immune systems get a workout. Non-parents — unless they are teachers or nurses perhaps — do not get the same exposure to infection.
Writing in the journal Scientific Reports, Miguel Portela said parents had less risk of dying from infection than non-parents and if they did, it was about five years later. He said that “a parent’s immune system is refreshed by a child’s infections at a time when their own protection starts wearing thin.” He added, “With this improved immune system, the parent has a better chance to defend whatever infections that might strike when old and weak and parenthood is rewarded in individual terms through an improved immunization against infections.” Naturally there are other reasons why some people live longer than others, but they may not be comparable with becoming a parent. The academics say that high income and house ownership are always associated with higher survival but less so than having children.
Mr. Portela admits the research is far from complete, saying that while the results “record a relationship between the presence of children and death rate, the specific transmission mechanisms remain unclear. He acknowledges the presence of other, perhaps behavioral factors in parents which result in changed death rate compared to individuals without children.” He adds, “While the relationships of lifestyle choices such as smoking, obesity, drinking and other behavioral factors with life expectancy and causes of death are well studied and understood, the same cannot be said for the individual decision to become a parent”.
1. Why did Mr. Portela say “parents had less risk of dying from infection than non-parents”?| A．Parents have healthier lifestyles. |
| B．Parents have less exposure to infection. |
| C．Parents have higher ability to fight against infections. |
| D．Parents have less experience to fight against infections. |
| A．By being exposed to their kids’ infection. | B．By working out with their kids. |
| C．By refreshing their kids’ life. | D．By strengthening their kids’ infection. |
| A．Rich life benefits parents more than having children. |
| B．Lack of sleep has nothing to do with life expectancy. |
| C．The presence of children can improve parents’ health |
| D．Behavioral factors contribute to higher death rate than having no children. |
| A．Parents and Non-parents | B．How to Achieve Longer Life Expectancy? |
| C．How Is Parents’ Immune Systems Changed? | D．Children’s Effect on Parents’ Immune System |
7 . How to Become a London Blue Badge Tourist Guide
To become a registered Blue Badge Tourist Guide working in London, you will need to take a course and gain accreditation from the Institute of Tourist Guiding.
The Course
The course typically lasts about 18 months and involves lectures in London and practical site visits, along with periods of self-study. Its main focus is London, but it also covers the major tourist destinations across the South East, so it helps to have a reasonable knowledge of London and destinations such as Windsor, Oxford and Stratford. It can also be useful to have language skills as a large number of guides provide tours in more than one language.
Applying for the Course
There is lots of interest in the course, so candidates are assessed by exam and interview before being awarded a place. You will find further information on the course fees and timelines on the Institute's website.
Programme Content
As part of the course, you'll learn how to develop and present highlighted tours of London's major attractions, together with a City of London walk and a panoramic coach tour. The practical side is matched by lectures covering a wide range of topics related to London, the various regional sites and the techniques of guiding.
Exams
During the course you'll take a number of written and practical exams and if you're successful you'll be awarded a Blue Badge, which is the industry's recognized symbol of professionalism in tourist guiding. It is also possible to take the exams without doing the course, but there are many benefits to doing so, not least the opportunity to meet and work with guiding colleagues.
1. What can be learned about The Course?| A．Lectures and self-study make up the whole course. |
| B．Language skills can be of great help. |
| C．It focuses on the major tourist destinations. |
| D．It has nothing to do with knowledge of London. |
| A．By taking exams. | B．By taking the course. |
| C．By having interviews. | D．By working with guiding colleagues. |
| A．A report | B．A notice. | C．A travel brochure. | D．An advertisement. |
8 . Picture this: It’s 2003 and your family has just finished arguing over which Netflix movie video tapes to rent that week. Movies come in the mail and the family watch them throughout the week. Then, fast forward to 2008, and you have started to watch TV shows on Netflix’s new platform.
Now, let’s come to the present. You sit down and open up Netflix on your TV and scroll （滚屏） for a while. Then check HBO GO. Finally, check Disney+. Then realize that you’re paying for three different streaming services, maybe more.
Let’s return to Netflix. More generally, streaming. There are over 100 video streaming services available, as well as quite a few music streaming, including YouTube Music, Google Play, and etc. The streaming world, at least to some, is on its way to getting out of control, with each service requiring its own monthly entertainment subscription. We haven’t even taken into account subscriptions like Microsoft Office and email newsletters. Subscriptions started out as a service of convenience, but now, the oversaturation may have become burdensome. The services believe customers will pay more to get the content they want. However, statistics show a growing frustration among consumers. With so many options, they find it harder than ever to make a decision on what to pick.
Not only does the oversaturation of streaming result in confusing navigation, it also creates a financial burden for the consumers. Let’s say if you want to watch The Handmaid’s Tale and Game of Thrones, which belong to two different services, you would have to pay nearly $50 a month to access both services, meaning it’s potentially more expensive, than cable.
People cut their cords （细绳） and went the streaming route because it was simpler and cheaper. Now, it’s just as inconvenient and difficult as cable was, if not more so, and unless you’re limiting yourself to one service, it’s not cheaper. Streaming will survive because we’re in a Golden Age of Media and because each service is able to create high-quality originals. But Golden Ages don’t last, and bubbles tend to burst. Until the unavoidable day when some product or service proves streaming out of date, we must suffer the choices in front of us. The next time you are scrolling through Netflix, Hulu, or whatever, and the over-choice is killing you, maybe you should just go pick up a book instead.
1. What is mainly talked about in the first two paragraphs?| A．Social progress has promoted the quality of life in the past decade. |
| B．Technology innovation results in different ways of relaxation. |
| C．Changes in home entertainment have brought us more options. |
| D．Netflix has been developing its service patterns. |
| A．The large number of subscriptions. |
| B．The frustration caused by poor service. |
| C．The rapidly developing entertainment market. |
| D．The confusing navigation resulting from streaming. |
| A．improve user satisfaction | B．raise entertainment costs |
| C．diversify entertainment forms | D．realize the resource sharing |
| A．the streaming service will have a bright future |
| B．reading has an advantage over streaming service |
| C．there will be some better service to replace streaming |
| D．nothing can end streaming services as long as media exists |
9 . What happens when you cross stem cells from a frog heart and frog skin? Not much-that is, until you program those cells to move. In that case, you've created a xenobot, a new type of organism that's part robot, part living thing.
Now a team of scientists has used living cells from frog embryos and assembled them into entirely new life-forms. These millimeter-wide xenobots can move toward a specific target and pull themselves through after being cut.
These are novel living machines," says Joshua Bongarch a computer scientist and robotics expert at the University of Vermont who co-led the new research. "They're neither a traditional robot nor a known species of animal. It's a new living, programmable organism.
Xenobots borrow their name from Xenopus laevis, the name for the African clawed frog from which the researchers harvested the stem cells. They combined together well two different kinds of cells-heart and skin cells. The heart cells are competent in expanding and contracting, which aids the xenobot in locomotion, and the skin cells administer structure. Besides, they can't accomplish tasks without the help of computers.
By studying these curious organisms, researchers hope to learn more about the mysterious world of cellular communication. Plus, these kinds of robo-organisms could possibly be the key to drug transmission in the body or greener environmental clean-up techniques.
“Most technologies are made from steel, concrete, chemicals, and plastics, which degrade(降解)over time and can generate harmful ecological and health side effects the authors note in a research paper. "When these xenobots finally do stop working, they fall apart harmlessly.
“Promising as these organisms are, when we start to mess around with complex systems that we don't understand, we're going to get unintended consequences Michael Levin, a biophysicist and co-author of the study, says in a press statement.
1. What do we know about the xenobot?| A．It is not easy to degrade over time. |
| B．It can recover itself after being cut. |
| C．It will never die with a computer inside. |
| D．It is named after a kind of American frog. |
| A．Appearance. | B．Position. |
| C．Application. | D．Movement. |
| A．recycle waste in nature. |
| B．replace certain damaged organs. |
| C．deliver medicine inside patients. |
| D．improve communication technology. |
| A．Xenobots can be put into the market soon. |
| B．Xenobots are created totally by accident. |
| C．More research should be done on xenobots. |
| D．It is hard for people to understand xenobots. |
10 . The spine (脊柱) stands at the center of your health, providing your body with structure and support. It also contains a major collection of nerves that deliver electric signals from the rest of the body to your brain. Since your spine is so central to health, it’s important to take care of it.
Staying in a good position is one of the most important things you can do to keep your spine healthy. A proper position means standing or sitting while keeping your spine straight, except for its natural bending. Positions play a vital part even when you’re asleep. Stomach sleeping is far from a good idea. Many people prefer sleeping on their side, which is in the interests of their spine. Sleeping on your back has lots of benefits yet can cause lower back pain and put some pressure on your spine.
Staying still for too long — even if your position is good — can be hard on your back. Especially if you work at a task most of the day, it’s important to get up and stretch (伸展) periodically. Therefore, exercise is also a key part in the health of your spine. Stretches can help the muscles (肌肉) around your spine relax. Strength exercises with light weights or body weight exercises like pushups can also help by strengthening the muscles. However, don’t overdo the exercise, as repeated movements can hurt the muscles around the spine, as trying to lift heavy weights with poor technique.
Your diet also affects the health of your spine because many vitamins are necessary for bones and nerves. In particular, vitamin B and omega3 fatty acids help keep nerves healthy. Another important part is vitamin D, which is required for strong bones. Vitamin D can come from some foods, but it’s also absorbed from sunlight, so it may help to do some exercises outside. At last, many of the actions necessary to keep a spine healthy are similar to those used to protect your health in other ways. So protect your back, and the rest of the body will benefit.
1. Which sleep position is best for our spine according to the passage?A． | B． |
C． | D． |
| A．Doing a proper amount of exercise. |
| B．Staying still in a good position. |
| C．Repeating a certain movement more. |
| D．Strengthening muscles of the whole body. |
| A．Vitamin B reacts with omega3 fatty acids. |
| B．Abundant vitamin D guarantees strong bones. |
| C．Vitamin D can’t be absorbed without sunlight. |
| D．Doing pushups outside increases vitamin D intake. |
| A．Good posture, good spine |
| B．Stay still, stay healthy |
| C．Healthy means, healthy spine |
| D．Proper exercise, proper weight |
