1 . Bred to be more sweeter, today’s cherries, bananas and apples taste different than they used — to but not necessarily better. Among fruit farmers, the word “quality” is now routinely used as a standard for “high in sugar”, though firmness, color and size are also considerations. In a recent study about ways to enhance the sweetness of fruit using “molecular (分子的) approaches”, a group of plant scientists wrote that, in general, the sugar content of many fruits are now higher than before owing to continuous selection and breeding. Modern apple varieties, the scientists stressed, were on average sweeter than older ones.
The sweetness of fruit depends not just on how it is bred but also on growing conditions, yield and harvest. The lead researcher, Sugiura, said, “If you could taste an apple harvested 30 years ago, you would feel the difference.” He believed that modern apples are picked so early that even if they are bred for sweetness, they often don’t develop their full character. The fragrance (香味) never develops in fruit that is harvested too early.
Jim Cooper, an apple farmer in England, is regretful to admit the fact that many people will never taste the “strawberry hint” in a really ripe Pearmain, a type of heritage apple. In a way, the rise of consistently sweeter fruit in our lifetimes has been a victory of plant breeding. After all, it’s a rare person who would seek out bitter grapes if they could have sweet ones instead.
But the sweetness of modern fruit is not without its problems, especially for people with diabetes (糖尿病), who have to reduce their intake of higher-sugar fruits. Fruit that is bred sweeter also tends to be lower in the chemicals that make it healthy. Considering health, maybe the real problem with modern fruit is that it has become yet another sweet thing in a world with sugar. Even grapefruits, which used to be quite bitter, are sometimes now as sweet as oranges. If you’ve never tasted a sour cherry, how can you fully appreciate a sweet one?
1. In what aspect is many fruits different from before?| A．Sugar content. | B．Soft skin. | C．Bright color. | D．High yield. |
| A．They are bred too early. | B．They taste so sweet. |
| C．They are losing a good flavor. | D．They need a higher yield. |
| A．Favorable. | B．Critical. | C．Ambiguous. | D．Indifferent. |
| A．It’s a wise choice to breed fruits for sweetness. |
| B．Breeding sweet fruits improves the quality of fruits. |
| C．Some fruits like grapes and cherries taste the same. |
| D．The sweetness of fruits will cause health issues. |
注意：
1. 写作词数应为 80 左右；
2. 请按如下格式在答题卡的相应位置作答。
参考词汇：magnitude 震级 load-bearing wall 承重墙
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3 . Why Do Mockingbirds Copy?
Mockingbirds live in North and South America. They are good copycats. They imitate other birds. But they can also imitate other animals. They can even make sounds like a piano or car alarm. Mockingbirds learn to sing many songs. Some learn more than 200 different songs. They can often trick people! But mockingbirds can’t trick other birds. If they can’t trick other birds, why do they copy sounds? They do it to attract and avoid other birds!
Males are loud singers, and they sing many songs. They always sing when they want to meet females. A male bird can sing most of the day and night. The singing attracts females. But it also keeps away other males. The longer a mockingbird lives, the more songs it knows. To show this characteristic, the male mockingbird sings all the songs it knows. A female mockingbird is attracted to a male who has lived a long time.
Mockingbirds usually sing short songs. They sing each sound several times. Then they move to the next sound. Female mockingbirds sing softly and less often than males. They usually sing at their nests in the winter to keep away other birds. When another bird comes near, the mockingbird makes a loud noise to frighten it. It’s amazing that the mockingbird can copy so many songs of other birds. Some songs are not easy to learn. The mockingbird must listen well to imitate the sounds. But a mockingbird also has good eyes and a good memory. When a person comes near its nest, the mockingbird remembers that person. It knows that person’s face after many years!
1. Mockingbirds are special because they can .| A．create songs | B．copy sounds |
| C．remember other birds | D．understand human’s words |
| A．size | B．eyesight | C．memory | D．voice |
| A．To recommend a course on birdlife. | B．To call on people to protect birds. |
| C．To give advice on feeding birds. | D．To introduce an interesting bird. |
4 . Chimps live in a male-dominated society, where most of their valuable partners are other males. However, as young male chimps become adults, they continue to maintain tight bonds with their mothers, a new study finds.
“The dramatic changes of adolescence are difficult for chimps, just like they are for humans,” says Elizabeth Lonsdorf, an expert on primates (灵长动物) at Franklin&Marshall College who was not involved in the study. “Sure enough,” she adds, “their moms remain a key social partner during this time.”
Previous research has shown chimp mothers provide their sons with support that goes far beyond nursing. Young male chimps that are close with their moms grow bigger and have a greater chance of survival. What’s more, losing their mothers after weaning (断奶), but before age 12，gets in the way of the ability of young chimps to win other males and reproduce.
To see whether this bond extends later into life, researchers followed 29 adolescent (9 to 15 years old) and young adult (16 to 20 years old) male chimps at a research site in Kibale National Park in Uganda and observed them from a distance for 3 years. The team found that the young adult males spent less time with their mothers than the adolescents did—26% vs. 76%. As the male chimps grew older and more independent, they began to travel over wider ranges and spent more time away from their moms.
However, when these young adult males happened to be in the company of their mothers, they acted just like the adolescents. They groomed (梳理) their moms just as often and kept track of them. “Many mothers remained the males’ ‘best friends’ or ‘social partners’ they associated with most frequently,” says study co-leader Rachna Reddy from Harvard University.
Such persistent ties are also common in humans after sons leave their mothers and live on their own—especially in tough times, Reddy says. “We really feel what it’s like to not be able to see our mothers when we want to in tough times. The importance of those bonds in our lives and the comfort we get from them have deep evolutionary roots.”
1. What do we know about Elizabeth Lonsdorf?| A．She is in favor of the new study’s finding. |
| B．She played a supporting role in the new study. |
| C．She did a different study on chimps’ adolescence before. |
| D．She thinks chimps actually live in a female-dominated society. |
| A．It may be easier for it to produce babies. |
| B．It may be easier for it to interact with other chimps. |
| C．It may be tough for it to defeat other males. |
| D．It may be much more aggressive than other males. |
| A．They took care of some motherless chimps. |
| B．They recorded the chimps’ social interaction. |
| C．They worked hard to win the chimps’ trust. |
| D．They limited the chimps’ range of movement. |
| A．To stress the purpose of the study. | B．To improve humans’ mother-son relationship. |
| C．To call on us to protect chimps. | D．To emphasize the significance of the study. |
A rainforest is an area
In the past hundred years, humans
Rainforests are often called the world’s drug store. More than 25％ of the medicines we use today come from plants in rainforests. However, fewer than l％of rainforest plants have been examined for their
6 . We’ve all heard the stories of an actor’s struggles before a career breakthrough: living a hard life, working part-time, being a couch potato before getting that major role. Shelby, the star of “A Dog’s Way Home”, has an unfortunate tale that could top them all. Before her big break, she was living in a landfill, rooting through garbage for her next meal.
Shelby’s big break came in April 2017, when animal-control officer Megan Buhler was driving in Cheatham County, Tennessee. Out on an unrelated call, Buhler spotted and approached what she recalled was a noticeably scared puppy emerging from the dump. “I knelt down and just said, ‘Oh, come here, baby,’” said Buhler. “She was so scared, but she came right up to me, and I was able to put her in my truck.” They headed to the county animal shelter, where the staff began calling the new resident Baby Girl.
Buhler and others didn’t know that 3,200 kilometers away, Hollywood was looking for a dog to play Bella in a film written by Cathryn Michon. The find-a-Bella job went to freelance trainer Teresa Ann Miller. Her mission was to search shelters nationwide for a dog that could play Bella. One day, Miller spotted Baby Girl’s adoption photo. “Honestly, it was a really good picture, and she was flat-out smiling,” Miller said. Then she met Baby Girl, and assessed her on personality and the ability to respond to simple commands. After assessment, she adopted Baby Girl from the shelter, renamed her Shelby and took her to California for training. Miller and Shelby had trained for just over three months before filming began. Then they were together each day on the set.
Most of the film’s reviews have praised Shelby’s performance. Variety made the comments “an amazing dog, perfect performance!”
Shelby has come a long way from the garbage dump. But Buhler said when she saw Shelby recently she just needed only a second to compare the movie star with the dog she found from piles of trash. “She’s exactly the same,” Buhler said.
1. Why does the author mention an actor’s struggles before a career breakthrough at the very beginning?| A．To clearly point out the main idea of the passage. |
| B．To attract reader’s attention by giving dramatic examples. |
| C．To introduce a dog’s similar but even more striking experiences. |
| D．To make a sharp contrast between an actor’s struggle and a dog’s struggle. |
| A．Her adoption picture. | B．Her personality and ability. |
| C．Her flat-out smiling. | D．Her miserable experiences. |
| A．The dog looked sad as before. |
| B．The dog was really excited to live such a happy life. |
| C．The dog returned to the piles of trash where she found it. |
| D．The dramatic change of the dog’s life hasn’t changed her inner quality. |
| A．The Trainer and Her Star Dog. | B．Shelby’s Unfortunate Story. |
| C．From a Landfill Puppy to a Movie Star. | D．The Success of “A Dog’s Way Home”. |
1. What type of animal does the woman like most?
| A．Cats. | B．Birds. | C．Dogs. |
| A．They can teach kids responsibility. |
| B．They are not easy to care for. |
| C．They are good friends. |
8 . Commercial airlines alone contribute around 3% of total global carbon emissions. But the industry is actively looking for green solutions in the form of sustainable jet fuel, and in one case, that fuel may have had a previous life as your household food waste. In a study released this week in the Proceedings of the National Academy of Sciences, researchers detail a method of transforming food waste into sustainable jet fuel that can be used in existing engines.
Biomass (生物质), such as manure (粪便) and food waste, can be transformed into bio-fuels, which are renewable liquid fuels made from organic matter. Derek Vardon, a senior research engineer at the National Renewable Energy Laboratory (NREL), says that their fuel worked as a mixture of 90% conventional petrol jet fuel and 10% alternative jet fuel required by the industry currently. They also show they could push it to a 70/30 mixture, which will be possible in real world with more time and testing.
Major airline companies are eager to get involved in sustainable aviation fuel because some sustainable solutions, such as battery-operated commercial planes, just aren’t possible yet with current battery technology. A battery-powered plane would be too heavy to fly long distances, so fuel that works in the same way as the fuel we have is a simpler way to trade out emission-heavy fossil fuels.
Vardon says that because the wet waste used in the process would normally go to a landfill (垃圾填埋场) and break down to release greenhouse gases, the process of making and using sustainable aviation fuel could actually have a negative carbon footprint when scaled up.
Commercial airlines are on board to find an affordable and sustainable solution to the carbon-intensive process of air travel. Airlines are looking to hit aggressive sustainability goals by 2050, including decreasing net carbon dioxide emissions by 50%.
1. Which of the following is used for sustainable airline power?| A．Fossil fuel. | B．Liquid fuel. | C．Battery power. | D．Biomass. |
| A．Fuel-powered planes are likely to travel lighter and farther. |
| B．Biofuel is environmentally friendly and sustainable. |
| C．It’s convenient to create the proper fuel mixture. |
| D．Biofuel proves less costly and easier to produce. |
| A．taking off. | B．holding a meeting. |
| C．participating in. | D．appearing on stage. |
| A．Alternative Energy to Fossil Fuel. |
| B．How to Get Fossil Fuel Sustainable. |
| C．Changing Food Waste into Airplane Fuel. |
| D．How to Decrease Carbon Dioxide Emissions. |
More than a fifth of all reptile species (爬行动物) are threatened with extinction, which could have
Although many reptiles live in dry
The study is not all depressing. Scientists noted that conservation efforts to help other animals are likely to be protecting reptile species as collateral (抵押品). “We found, surprisingly, that if you set out
Yet reptiles also require direct,
How do you feel about bees? Do you get annoyed when they buzz around you and do you fear their mission is just to sting you? Love them or loathe them, these little insects are extremely important creatures, and without them we might starve.
Bees deserve some respect — they give us honey, and they play their part either pollinating the many vegetables and fruits we eat directly or pollinating the food for the animals that we then consume. In fact, they are the world’s most important pollinators. That’s not all — a study by the University of Reading in the UK, found bees and other pollinating insects have a global economic value of around £120bn ($150bn) and contribute around £690m ($850m) to the UK economy every year.
So, bees are worth protecting, and although a small number of bee species are vital for crops such as oilseed rape, apples and strawberries, experts say we should be taking care of all our bees. Researchers say conservation efforts should be aimed at a wide number of species — even those that currently contribute little to crop pollination —– in order to maintain biodiversity and ensure future food security.
Unfortunately, in recent times, bee populations have been declining due to pesticides, parasites, disease and habitat loss. It’s something we should be worried about because, as Gill Perkins, chief executive of the Bumblebee Conservation Trust, told BBC Future website: “They provide a whole ecosystem service.” The recent lockdowns caused by the coronavirus pandemic seem to have given bee populations a little boost because they faced less human disturbance, traffic and polluting fumes.
Conservationists hope, going forward, people will appreciate bees more and encourage them to thrive as they reconnect with nature. Gill Perkins says, “They are beginning to realise how their mental health and wellbeing is supported by nature — particularly by bumblebees, which are so iconic and beautiful and buzzy.” So, it really seems time to give bees a second chance.
1. Please state the function of paragraph 1.2. What reasons have contributed to the decrease in bee populations?
3. Is the following statement true or false? Please provide evidence from the passage.
Gill Perkins says reconnecting with nature helps improve the mental health of bumblebees.
4. What is the main idea of this passage?
