The worldwide 20th century “Green Revolution”, which saw huge year-by-year increases in global grain yields (产量), was fueled by the development in the 1960s of new high-yielding dwarfed (矮小) varieties known as Green Revolution Varieties (GRVs).
These dwarfed GRVs are common all over the world in today’s wheat and rice crops. Because they are dwarfed, with short stems, GRVs devote relatively more resources than tall plants to the growth of grains rather than stems, and are less likely to suffer yield losses from wind and rain damage. However, the growth of GRVs requires farmers to use large amounts of nitrogen fertilizers (氮肥) in their fields. These fertilizers are costly to farmers and cause extensive damage to the natural environment. The development of new GRVs combining high yields with reduced fertilizer requirements is thus a global agricultural goal.
Researchers at the University of Oxford and the Chinese Academy of Science have discovered for the first time a gene that can help reach the goal. Comparing 36 different dwarfed rice varieties, the researchers identified a novel natural gene that helps increase the rate at which plants make use of nitrogen from the soil. This gene, called GRF4, can increase the amount of a protein (蛋白质) in plant cells. GRF4 is actually a promoter that encourages the activity of other genes—genes that promote nitrogen uptake (摄入). Professor Harberd said, “Increasing GRF4 levels could contribute to an increase in the grain yields of GRVs, especially at low fertilizer input levels.”
The researchers say the latest rice variety containing GRVs should now become a major target for farmers in increasing crop yields and fertilizer use efficiency, with the aim of achieving the global grain yield increases necessary to feed a growing world population at a reduced environmental cost. It is very urgent at the moment.
Professor Harberd added, “This study is an example of how studying fundamental science objectives can lead rapidly to potential solutions to global challenges. It shows how the discovery can enable chances for food security and future new green revolutions.”
1. What can we know about dwarfed GRVs?| A．They have higher yield and taller stems. | B．They are a “double-edged sword”. |
| C．They are environmentally friendly. | D．They can be easily affected by weather. |
| A．Increasing the rate of nitrogen use. | B．Producing cheaper nitrogen fertilizers. |
| C．Using fewer fertilizers to produce more grains. | D．Finding a gene to solve agricultural problems. |
| A．It promotes other genes’ activity. | B．It increases the output of crops. |
| C．It takes in nitrogen from the soil. | D．It lowers fertilizer input levels. |
相似题推荐
【推荐1】Steve Davies, a 23-year-old board designer in Wales, is developing a surfboard made from mycelia (菌丝体) instead of plastic.
A 2022 report showed that more than 400, 000 boards are made each year. The global market for surfboards reached $2.2 billion in 2020 and is expected to reach $3.2 billion by 2027. But about 80% of boards are made from plastic, which can take hundreds of years to break down. This will be a serious problem for the environment as the market grows.
“And even when it does break down, it can go into fish’s ecosystem (生态系统), which means that humans will end up eating this plastic,” Davies said.
Davies made his first surfboard in 2020, but the experience showed him many harmful materials were produced in making each board. During his final year at university, he started looking into mycelia and making his beloved sport more environment-friendly.
“My family owns a farm with horses, so I was quickly able to collect substrate material (基料) in the form of horse bedding, to allow the mycelia to grow in,” Davies explained. “This gave me an idea to start a surfboard business—growing surfboards on a farm near the beach and using waste materials from that very same farm, reducing the transport of materials, and therefore reducing carbon (碳) given out into the environment.”
“In the right conditions, we will grow a mycelium board in around 21 days,” Davies said. “The dream would be to make it the new standard. Connecting with nature would be the new design rules and that would be really cool. We’re using the sea and we should give back to the sea.”
1. What do the numbers in Paragraph 2 mainly show?| A．Going surfing costs a lot of money. | B．Surfing is popular with young people. |
| C．Designing surfboards is a good business. | D．Making eco-friendly surfboards is necessary. |
| A．To explain a rule. | B．To present a reason. |
| C．To make a comparison. | D．To share an experience. |
| A．Why Davies loved to design surfboards. |
| B．What made Davies’ surfboard business possible. |
| C．Why Davies wanted to study mycelia at university. |
| D．How Davies collected substrate material to make surfboards. |
| A．He supports environment-friendly products. | B．He hopes to succeed in selling surfboards. |
| C．He loves to get designing ideas from sea. | D．He dreams of creating cooler surfboards. |
【推荐2】What do you use to unlock your cellphone? A password? A fingerprint? Or simply a glance?
On September 12, 2017, Apple introduced its iPhone X, which has an eye-catching feature—Face ID.
With Face ID, Apple says, you can unlock your new iPhone by just looking at it. It is powered by a so-called TrueDepth camera system built into the front of the iPhone X.
When the camera system sees a person’s face, it uses 30,000 unseen dots to “map” the shape and outline of the face. A mathematical model of the face will then be created and stored in the phone.
The next time the person looks at the iPhone X, the same dots are mapped onto his or her face and compared to the stored model. If the two match, then the phone unlocks. This happens in less than a second.
Apple says the system is smart. If you change your hairstyle, put on sunglasses or makeup, or use the phone in the dark, Face ID still works.
Although the technology sounds fancy, there are still concerns. For example, will Face ID work for twins?
According to Apple, the chance of others to unlock your iPhone X using Face ID is one in a million. Face ID can tell the difference between twins, but the error rating（出错率）rises. So one would need to set a password then.
Apple also emphasizes that Face ID only unlocks when you stare at it. It is what Apple calls “attention aware”. So the phone won’t unlock if you are just glancing at the phone for the time. It won’t work either if someone puts the phone at your sleeping face or your photo.
1. Face ID helps iPhone X users to ________.| A．get their phones more eye-catching |
| B．make the phone camera powerful |
| C．unlock their cell phones quickly |
| D．create and store their face model easily |
| A．It compares the face model with the user’s face later. |
| B．It remembers the users’ faces by taking their pictures. |
| C．It uses a map to store face models of its users for use. |
| D．It matches the users’ faces with dots in the system. |
| A．they wear makeup | B．the users are twins |
| C．they change the hairstyles | D．they use it without lights |
| A．The introduction of the iPhone X |
| B．The features of the iPhone X |
| C．The iPhone X recognizes a face |
| D．Unlock the iPhone X by a stare. |
【推荐3】Want to get your package delivered via robots?Now there’s an app for that.If you live in Washington,D.C.,or Redwood,you may have glimpsed a small,boxy robot rolling along a local sidewalk,minding its own business,but attracting the attention of many curious onlookers.
The autonomous machines were part of a pilot program last year by Starship Technologies focusing on delivering meals from local restaurants in dozens of cities around the world.This week,the company unveiled plans to broaden its delivery service beyond food to include packages,a move that led it to declare itself “the world’s first robot package delivery service”.The next time you order food,this cute robot might roll up to deliver it.The package delivery service is not available to everyone yet.
The wheeled robots have a top speed of 4 mph and can detect obstacles from 30 feet away.“The robot can operate through anything,” Nick Handrick,head of operations for Starship’s D.C.office,said,“If you have something in the way—a stick—it’s able to climb over it.”
To sign up for the service,which costs a little more than $ 10 per month,customers need to download the company’s app.Customers then create a “Starship Delivery Address”,a unique address inside a Starship facility,where they can have packages sent from some places.Once a package is delivered to the Starship address,customers receive a text notification that allows them to schedule a home delivery via robots.The robots are opened by customers via a mobile phone code.
Barriers exist for robotic ground delivery,with many states requiring that humans be in control of delivery robots.Those regulations haven’t stopped Starship Technologies from accumulating experience on streets around the globe ahead of the company’s latest launch.The company says its robots have covered more than 125,000 miles in more than 100 cities in 20 countries.
1. What is the last paragraph mainly about?| A．The good news of the service. |
| B．How the robotic delivery works. |
| C．The disadvantages of the robotic delivery. |
| D．Robotic delivery develops despite challenges. |
| A．A New Robot Was Invented |
| B．Wheelless Robots Are on the Way |
| C．How Robots Deliver Packages |
| D．Packages Will Be Delivered by Robots |
| A．It is part of a trial project by Starship Technologies. |
| B．The robotic delivery is available to everyone at present. |
| C．You can use the service free of charge via smart phones. |
| D．The robots are opened by customers with a text notification. |
| A．Revised. | B．Released. |
| C．Restored. | D．Reset. |
【推荐1】Hipster Greenport: 4 places to eat, shop and visit
Greenport may date back to the 1630s, but it’s feeling pretty of-the-moment right now. Here are four places that embody the old-meets-new energy of the village:
Claudio’s
If you’ve been to Greenport, you can’t miss Claudio’s — it’s where generations of Long Islanders have made a tradition of eating, whether inside the main restaurant or at the floating dock-bar. The new owners have added fresh elements: Baccano Pizza by Nino, which offers a variety of slices and pies until as late as 2 a.m. on Fridays and Saturdays — is right by the dock entrance.
Little Creek Oyster Farm & Market
It’s little spots like this that tell the current Greenport story. There’s no sign or advertising for this tiny house changed from the cabin of an old ship that’s practically hidden down Bootlegger’s Alley near Mitchell Park. But there they are — streams of people who come to enjoy the fresh oysters while drinking local craft beer, with a waterside view.
The Times Vintage
Nostalgia (怀旧) for bygone times runs high in this 1909 building, which once served as the base for the Suffolk Times newspaper. These days, this well-designed shop sells vinyl records (黑胶唱片) and loads of old-fashioned clothing and home decoration items including mid-century highball sets.
Greenport Fire
Heat comes in many forms and several are sold here — hot sauces, cigars and candles. Consult the chalkboard for the current sauce offerings or browse cigars such as a hand-rolled Honduran Leaf by Oscar or the Gurkha Cellar Reserve made with 18-year-aged tobacco.
1. What’s special about Greenport?| A．It is a place full of energy. |
| B．It is a famous port in the world. |
| C．It is a combination of new and old. |
| D．It is a popular place of interest. |
| A．You can enjoy delicious oysters. |
| B．You can buy some old things. |
| C．You can find hand-rolled cigars. |
| D．You can have Baccano Pizza. |
| A．Claudio’s |
| B．Little Creek Oyster |
| C．Greenport Fire |
| D．The Times Vintage |
【推荐2】Yangzhou paper cutting, with a history of 2,000 years, can be dated back to the Sui Dynasty, making Yangzhou one of the places where paper cutting first became popular.
In the Sui Dynasty, the people of Yangzhou would cut colourful paper or silk and satin (缎子) to celebrate festivals. It is said that Emperor Yang came to Yangzhou three times. In winter, the flowers and trees in the garden became dry and weak. The emperor ordered the gril servants to cut fine silk and satin into flowers and leaves and use them to decorate the trees and lakes. Since then, “colorful cutting” has become a popular art in Yangzhou.
In the Tang Dynasty, the paper cutting industry was highly developed and a large amount of high-quality paper was made as presents to the Court (宫廷).
In the Qing Dynasty, because of the economic development, the people of Yangzhou became interested in wearing fine clothing, especially embroidered (刺绣的) clothing. The embroidered designs were based on paper-cuts, the most well-know of them was from Bao Jun, a paper cutting master. He won a high reputation (名声) as Magic Scissors for his wonderful cutting skills.
After the People’s Republic of China was started, the Chinese government accepted the importance of paper cutting like many other arts and skills. In 2007, China Paper-cuts Museum opened to the public in the back garden of the Wang’s Residence (住所), Yangzhou, greatly helping the development of Yangzhou paper cutting.
1. When did “colourful cutting” become a popular art in Yangzhou?| A．In the Sui Dynasty. | B．In the Tang Dynasty. |
| C．In the Ming Dynasty. | D．In the Qing Dynasty. |
| A．种植 | B．装饰 | C．浇水 | D．砍伐 |
| A．In 2007. | B．In 2008. | C．In 2009. | D．In 2010. |
| A．How to make paper cutting. |
| B．The way to cut paper. |
| C．The importance of Yangzhou paper cutting. |
| D．The history and development of Yangzhou paper cutting. |
【推荐3】Some people often wonder whether they are fighting a battle with their genes to maintain a healthy weight. In fact, researchers have provided plenty of evidence that people are born with tendencies to be lighter or heavier. For example, studies of identical twins have revealed great similarity in their overall weight. Part of this similarity may be explained by the finding that some people are born to burn a lot of calories just through ordinary day-to-day activities while others are not. Those who are not are more at risk for weight gain.
Researchers have discovered some of the actual genetic mechanisms (机制) that may make some individuals more likely to be obese (肥胖的). For example, a gene has been found that appears to control signals to the brain that enough fat has been stored in the body in the course of a meal — so the individual should stop eating. The gene influences the production of leptin (瘦蛋白), which keeps appetite under control. If leptin doesn’t work well, it is likely that individuals will continue to eat. Thus the gene that controls leptin appears to have a critical influence on the potential for obesity.
The confirmation that leptin plays a role in weight control has encouraged researchers to identify and understand other weight-related genes. Recent attention has focused on a gene called GAD2. GAD2 helps control the amount of the neurotransmitter (神经递质) GABA. In general, when more GABA is available, appetite is increased. For that reason, people who have a form of GAD2 that allows more GABA to be available may be at risk for overeating. You can see that GAD2 is not directly an obesity gene. Rather it has an indirect influence on obesity through its direct influence on GABA.
Genetic research holds out the promise of innovative solutions to obesity. Researchers hope that an understanding of the link between genus and weight control will enable them to provide new drug treatments. Nonetheless, even the most optimistic researchers provide a warning: “Innovative drugs will be effective only when they are used along with lifestyle changes.”
1. What does the author want to explain by giving the example of twins?| A．It is hard to maintain a healthy weight. | B．Being fat or thin is genetic ally related |
| C．The twins are usually of similar weight. | D．An individual ‘ body can burn calorie. |
| A．Poor appetite. | B．All varieties of GAD2 |
| C．Effective leptin. | D．Extra amount of GABA. |
| A．Adopt advanced means. | B．Learn more about genetic effects. |
| C．Keep good living habits. | D．Change the weight-related gene. |
| A．How does genetics contribute to obesity? | B．What impact does eating have on weight? |
| C．How many genus determine who is obese? | D．Why do many people become overweight? |
