1 . The green and red watermelon is a sweet, refreshing summer snack. But it wasn’t always so sugary or brightly colored. So what did watermelons originally taste and look like, and from where did they come?
The fruit isn’t from the Fertile Crescent of ancient Mesopotamia, as so many other domesticated (家养的) crops are, research shows. Susanne Renner, a scientist, and her colleagues carried out comprehensive genetic sequencing (基因测序) of the domesticated watermelons — the kind you might find on supermarket shelves — along with six wild watermelon species.
“We found the modern genomes (基因组) of the domesticated watermelon are more closely related to the Sudanese wild type than any other that we analyzed,” she said. The Sudanese wild watermelon has some obvious differences from the domesticated version. “The flesh is white and not very sweet, and it’s mainly used as animal feed,” Renner said. Nevertheless, the genetic similarity between the two species led the researchers to conclude that the Sudanese fruit is probably a precursor (前身) to the red and sweet domesticated watermelon.
It’s likely that ancient farmers grew non-bitter varieties of the wild watermelon and thus increased its sweetness over many generations through the domestication process. The red color is probably also thanks to artificial selection, in which farmers likely favored and selectively bred red fruit.
We already knew that the ancient Egyptian king Tutankhamun was buried with watermelon seeds 3,300 years ago, yet that isn’t sufficient proof of a domesticated, sweet watermelon. But then, Renner found an image of a watermelon-like fruit on an ancient Egyptian tomb painting, thought to be more than 4,300 years old. In a separate tomb, another image showed the watermelon cut up in a dish alongside other sweet fruits. This realization, coupled with Renner’s genetic findings, suggests that the watermelon was most likely domesticated around that time either in Egypt or within trading distance of the ancient empire.
“Historically speaking, that’s a very significant finding,” said Hanno Schaefer, a professor of plant biodiversity. “It’s becoming clearer that we’ve greatly neglected the North African region. We’ve focused too much on the Fertile Crescent and we need to invest more resources into studying the agriculture of North Africa.”
1. What can we learn about the Sudanese wild watermelon?| A．It is brightly colored and sugary. |
| B．It is consumed mainly by animals. |
| C．It has no connection with the domesticated type. |
| D．It has more differences than similarities to the domesticated type. |
| A．More resources will be devoted to agriculture research in South Africa. |
| B．The domesticated watermelon has a history of at least four thousand years. |
| C．The domesticated watermelon probably developed from the Sudanese type. |
| D．Few domesticated crops are from the Fertile Crescent of ancient Mesopotamia. |
| A．The history of the Sudanese wild watermelon. |
| B．Where wild watermelons actually come from. |
| C．The characteristics of domesticated watermelons. |
| D．How domesticated watermelons came into being. |
| A．Favorable. | B．Doubtful. | C．Critical. | D．Tolerant. |
2 . Like people, dogs tend to have unique personalities. Some of a dog’s personality traits (特点) are completely individual, but many traits are predictable based on the breed (品种). Knowing the common traits of certain dog breeds enables you to choose a dog whose personality matches well with your lifestyle.
| Siberian Husky You may already know that Siberian Huskies have a historical role as sled dogs. This breeding makes them get along well with other animals, but you have to ensure that they have enough space to run safely. Unlike some of the other working dogs, Siberian Huskies tend to be too friendly to be very good guard dogs. |
| Bulldog The Bulldog is friendly and loyal. They tend to be calm by nature, but they still enjoy getting out for walks. A small amount of exercise is important for weight-management given the fact that their calm nature can make them come off as lazy. Bulldogs are great companions for the old and are courageous and steady. |
| Cocker Spaniel The Cocker Spaniel’s long ears and curly hair are a major outward sign of their sweet, friendly personalities. As sporting dogs, they were raised to help hunters and play with kids. If they don’t get enough energy out, though, they can become down and destructive. |
| Dachshund The Dachshund’s small physical size is no match for their big personality. Their short legs do not make Dachshunds great running or hiking buddies, but that does not mean they are low-energy. They are great guard dogs-brave, loyal, and a bit stubborn. |
| A．A Siberian Husky. | B．A Bulldog. |
| C．A Cocker Spaniel. | D．A Dachshund. |
| A．Every dog has its day. | B．If you want a dog, get a dog. |
| C．A good dog deserves a good bone. | D．An old dog won’t learn new tricks. |
| A．A pet clinic brochure. | B．A personality test book. |
| C．A biological research. | D．A dog breeding website. |
3 . When Abdus Salam looks across the garbage-filled river near his home in one of the major clothing producing districts in Dhaka, the capital of Bangladesh, he remembers a time before the factories moved in. “When I was young there were no clothing factories here. We used to catch fish in the river,” he said. The river beside him is now black like ink. Waste from nearby clothing factories has polluted the water.
Fashion is responsible for up to one-fifth of industrial water pollution, thanks in part to weak management in producer countries like Bangladesh, the world’s second biggest clothing producing country, where wastewater is commonly differed directly into rivers and streams. The wastewater not only hurts the environment, but pollutes drinking water sources.
Once in waterways, poisonous chemicals from dye (染料) build up to the point where light is prevented from coming through the surface, reducing plants’ ability to photosynthesize (进行光合作用). This lowers oxygen levels in the water, killing plants and animals. These chemicals and heavy metals can also build up in the body, increasing the risk of serious illnesses and skin problems. What’s worse, chemical-rich water is also used to water crops, with one recent study finding that dyes were present in vegetables and fruit grown around Savar, just north of Dhaka.
Luckily, change is coming. In Bangladesh, there are signs clothing producers are taking environmental responsibility more seriously, with brands committing to initiatives, such as the Partnership for Cleaner Textile, that title water, energy and chemical use in the industry. Shahab Uddin of Bangladesh’s Ministry of Environment, Forest and Climate Change said a range of measures were being taken to address pollution, including updating conservation and environmental laws, giving fines to polluters, setting up centralized treatment plants, and working with international development partners to improve wastewater treatment. And under a new environmental policy called Zero Liquid Discharge, dyeing, finishing and washing industries must submit a time-bound plan to reduce, recycle and reuse wastewater.
“There is definitely from for further improvement. These challenges cannot be solved overnight,” Uddin added.
1. What is the main purpose of the first paragraph?| A．To blame clothing factories for river pollution. | B．To introduce Bangladesh’s clothing industry. |
| C．To call for the closure of clothing factories. | D．To recall the good old days in Dhaka. |
| A．It is the biggest clothing producing country. | B．It causes 20%of the world’s water pollution. |
| C．It has poor control over wastewater discharge. | D．It suffers from serious drinking water shortages. |
| A．The difficulty of dealing with poisonous chemicals in waterways. |
| B．The damaging effects of wastewater from the fashion industry. |
| C．The chemicals from dyes negatively affecting photosynthesis. |
| D．The way to remove harmful chemicals from the food chain. |
| A．Hand in a plan to treat wastewater. | B．Establish centralized treatment plants. |
| C．Pay high fines for discharging wastewater. | D．Join international groups to deal with wastewater. |
4 . Birds that are literally half-asleep — with one brain hemisphere alert (警惕的) and the other sleeping — control which side of the brain remains awake, according to a new study of sleeping ducks.
Earlier studies have documented half brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere’s eye stays open and alert. Birds also can sleep with both hemispheres resting at once.
Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable, end of the row sleepers.
Sure enough, in the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction.
Also, birds dozing at the end of the line resorted to single hemisphere sleep, rather than total relaxation, more often than inner ducks did. Rotating (轮换位置) 16 birds through the positions in a four duck row, the researchers found outer birds half asleep during some 32 percent of dozing time versus about 12 percent for birds in internal spots.
“We believe this is the first evidence for an animal behaviorally controlling sleep and wakefulness simultaneously in different regions of the brain,” the researchers say.
The results provide the best evidence for a long-standing guess that single-hemisphere sleep evolved as creatures scanned for enemies. The preference for opening an eye on the lookout side could be widespread, he predicts. He’s seen it in a pair of birds dozing side-by-side in the zoo and in a single pet bird sleeping by a mirror. The mirror side eye closed as if the reflection were a companion and the other eye stayed open.
Useful as half sleeping might be, it’s only been found in birds and such water mammals (哺乳动物) as dolphins, whales, and seals. Perhaps keeping one side of the brain awake allows a sleeping animal to come up occasionally to avoid drowning (溺死).
Studies of birds may offer unique insights into sleep. Jerome M. Siegel of the UCLA says he wonders if birds’ half brain sleep is “just the tip of the iceberg”. He guesses that more examples may turn up when we take a closer look at other species.
1. A new study on birds’ sleep has revealed that ______.| A．half brain sleep is found in a wide variety of birds |
| B．half brain sleep is characterized by slow brain waves |
| C．birds can control their half brain sleep consciously |
| D．birds seldom sleep with the whole of their brain at rest |
| A．they have to watch out for possible attacks |
| B．their brain hemispheres take turns to rest |
| C．the two halves of their brain are differently structured |
| D．they have to constantly keep an eye on their companions |
| A．the phenomenon of birds dozing in pairs is widespread |
| B．birds prefer to sleep in pairs for the sake of security |
| C．even an imagined companion gives the bird a sense of security |
| D．a single pet bird enjoys seeing its own reflection in the mirror |
| A．alert themselves to the approaching enemy |
| B．emerge from water now and then to breathe |
| C．be sensitive to the ever-changing environment |
| D．avoid being swept away by rapid currents |
| A．half-brain sleep has something to do with icy weather |
| B．the mystery of half-brain sleep is close to being solved |
| C．most birds living in cold regions tend to be half sleepers |
| D．half-brain sleep may exist among other species |
5 . I recently gave a talk about zero waste living to university students. During the Q&A afterward, the unavoidable question of cost came up. One student pointed out that he “can’t afford to buy $30 toothpaste.” While the $30 price may be a bit generous, the student did raise a good point that buying zero-waste products is often more expensive than the overly-packaged traditional ones.
I tried to handle the question as best I could in the moment, but I kept thinking about it afterward. I’m writing about it because I’m sure many others have similar doubts about their own abilities to reduce waste without breaking the bank.
First, once you begin to explore the zero waste world, you quickly realize how pointless many products in your life are. You start using fewer, buying less, and using them interchangeably. Soon you’ll find yourself spending less money overall, which balances the higher cost of the zero waste ones. The total number of products in my bathroom decreased by 50% when I became more focused on waste reduction.
Second, if you stop to examine those zero-waste products, you’ll see that they are usually of better quality. Companies usually redesign their packaging to be reusable, upgrading them to be healthier, safer, and greener. So you’re paying extra money not just for non-disposable (非一次性的) packaging, but also for a better product that does less harm.
In my experience, higher-quality skincare products last longer than cheap ones. My personal habits have developed gradually, too. Knowing an item costs more leads me to use it in small quantities and use it to the very end. Moreover, I sometimes even make my own. The price-per-unit is cheap.
To quote Lindsey Miles, a zero waste blogger, “Zero waste is not about what we can afford to buy. It is about what we choose not to buy.” To that student who got me thinking about this, I’d recommend starting with what matters to you. Over time you will figure out where you get the most value for your money. In return, you’ll gain a sense of liberation from the consumer culture, and a rewarding sense of accomplishment.
1. What can we benefit from zero waste products?| A．Saving money regularly. | B．Balancing the higher cost. |
| C．Living a convenient life. | D．Spending money more wisely. |
| A．Zero-cost. | B．Top-grade. | C．Non-breakable. | D．Well-packed. |
| A．To teach a life lesson. | B．To introduce a social issue. |
| C．To promote a new product. | D．To encourage a lifestyle. |
6 . What do you do with an orchid (兰花) after its petals have fallen off?
Just like most things rare and beautiful, they don’t
I can’t
This year,
A few of the plants were moved to a table in the living room, and some others were
At some points in life, even the most magnificent events come to a(n)
Sure, you can
My wife kept moving the plants around the house, looking for the right light.
Yes, you can
| A．Because | B．Although | C．Unless | D．If |
| A．continue | B．last | C．change | D．go |
| A．fall | B．grow | C．open | D．disappear |
| A．help | B．stop | C．keep | D．stand |
| A．therefore | B．also | C．anyway | D．though |
| A．removed | B．ignored | C．placed | D．sold |
| A．questioning | B．wondering | C．regretting | D．doubting |
| A．decision | B．conclusion | C．agreement | D．end |
| A．nothing | B．everything | C．something | D．anything |
| A．style | B．cycle | C．pattern | D．story |
| A．stick to | B．break down | C．build up | D．give up |
| A．rescue | B．defense | C．notice | D．way |
| A．Generally | B．Normally | C．Surprisingly | D．Sadly |
| A．lose | B．miss | C．gain | D．keep |
| A．fair | B．big | C．rare | D．slim |
7 . In 2004, Pen Hadow became the first person to trek (跋涉) to the North Pole alone, without being resupplied on the way. That meant swimming through cold waters, and risking meeting polar bears. Just eight months later, he made a similar trip to the South Pole. Now he is back in the Arctic again, preparing for a more ambitious expedition (远征). This time, however, more significance is attached. Pen and two colleagues will set out on a three-month, 1000-kilometre trek to the North Pole, taking detailed measurements of the thickness and density of the ice. Nobody has ever done this before, and he knows the results will be of vital significance to the scientific community. This will be the truest picture so far of what global warming is doing to the ice that covers the polar region.
Pen and his wife, Mary, live in the country with their two children. “It’s much harder to be away from them this time,” he admits. They were one and five when I last went, and I made a mistake in the way I said goodbye. I thought it would be a good idea to say to my son, “You’re the man of the house now, look after your mum and your sister.” He absolutely took it to heart, asking his mum how she was all the time, but the stress eventually became too much. While it was well intentioned, it was an unfair thing to do.
He is spending these last days before departure preparing his things. With him will be Ann Daniels, one of the world’s leading polar explorers, and the photographer, Martin Hartley. They will be supported by a crew of six, flying in supplies. Being part of a team is actually more stressful to someone like him. Besides, something else is on his mind too. “I’m going to be 47 on Thursday. I’ve done far less training.” Why? “Organizational things always seem more urgent. So I’m almost fearful of what I’m going to ask of myself.”
Pen believes his mission reconnects exploration with the search for knowledge that drove previous generations into the unknown. “Making it to the North Pole was a personal ambition and of limited value to anyone beyond the polar adventuring community. This time, scientists will profit from the data, and we’re creating a platform to expose as many people as possible to what’s happening in the Arctic Ocean. This is important work, and nobody can do it but us,” he says. “Our skills, which are otherwise not that necessary, have become really relevant. Suddenly, we’re socially useful again.”
1. What can we learn about Pen Hadow’s opinion of the new expedition in paragraph 1?| A．He is aware of its huge importance. |
| B．He feels certain that it will be stressful. |
| C．He thinks it similar to his previous journeys. |
| D．He is confident with the help of a regional picture. |
| A．He started to feel unwell. |
| B．He memorized his father’s words. |
| C．He was afraid of the responsibility. |
| D．He carried out his father’s words carefully. |
| A．Whether he will be mentally prepared. |
| B．Whether supplies will be enough in time. |
| C．Whether he will still be fit enough to take part. |
| D．Whether the arrangements will turn out well. |
| A．uncertain if it will collect information |
| B．doubtful about its long-term usefulness |
| C．proud that they can contribute to scientific research |
| D．relieved that the general public will be more supportive |
1. Where are the two speakers?
| A．On the street. | B．In a park. | C．At a square. |
| A．Golden retriever. | B．Chihuahua. | C．Samoyed. |
| A．He’s cute. | B．He’s shy. | C．He’s dangerous. |
| A．A large-sized dog. | B．A brave dog. | C．A smart dog. |
9 . Birds rely on their keen sense of hearing to detect prey(猎物) and identify other birds on the basis of their songs. In fact, birds have better hearing than humans, so they hear with much more detail. So how do birds hear?
Birds and humans both have an inner ear and a middle ear. However, birds differ from humans in that they lack an external ear structure. Where humans have an outer ear organ, birds have a funnel-shaped(漏斗状的) opening that functions as their outer ear, located on each side of their head. These openings are usually positioned behind and slightly below a bird’s eyes and are protected by soft feathers.
The position of a bird’s head also plays a role in its hearing abilities. Scientists have determined that noises register(显示) at different frequencies on each side of the bird’s head. Depending on the angle from which the noise originates, it registers with a certain frequency in the left eardrum(耳膜) but with a different frequency in the right eardrum. This allows the bird to locate a sound’s origin.
Let’s take a look at owls. They are known for their extremely accurate hearing, which helps them locate prey at night. This hearing ability is partly due to the unbalanced arrangement of the ear openings, with one opening being lower than the other. Sounds register in these openings at slightly different times. Owls can use this time difference, which is only 30 millionths of a second, to determine whether the sounds are coming from their left or their right. Other birds of prey have small covers in front of their ears that help them determine whether sounds are coming from above them or below them. Some owls do appear to have ears on the top of their head, but those are actually feathers controlled by small muscles under the skin that do not affect their hearing at all.
1. According to paragraph 2, what is the major difference between birds’ ears and humans’ cars?| A．Size | B．Position. | C．Structure. | D．Function. |
| A．Each side of the bird’s head. |
| B．Sound quality around the bird. |
| C．The angle from which the noise comes. |
| D．The difference in frequencies between the eardrums. |
| A．To give examples. | B．To present the main idea. |
| C．To draw a conclusion. | D．To compare different opinions. |
| A．Different Senses of Birds | B．Amazing Abilities of Birds |
| C．The Secret of Birds’ Hearing | D．The Origin of Birds’ Hearing |
10 . A report from the UN warns that countries’ current commitments would reduce carbon by only about 7.5% by 2030, far less than the 45% cut, which scientists say is needed to limit global temperature rises to 1.5°C, the aim of the COP26 summit.
António Guterres, the UN secretary-general, described the findings as a “thundering wake-up call” to world leaders, while experts called for action against fossil fuel companies.
Although more than 100 countries have promised to reach net zero emissions around mid-century, this would not be enough to avoid climate disasters, according to the UN emissions report, which examines the shortfall (差额) between countries intentions and actions needed on the climate. Many of the net zero commitments were found to be unclear, and unless accompanied by strict cuts in emissions this decade would allow global heating of a potentially disastrous extent.
Guterres said: “The heat is on, and as the contents of the report show, the leadership we need is off. Far off. Countries are wasting a massive opportunity to invest Covid-19 finance and recovery resources in sustainable, cost-saving, planet-saving ways. As world leaders prepare for COP26, that is another thundering wake-up call. How many do we need?”
Inger Andersen, the director of the UN Environment Programme (UNEP) said: “Climate change is no longer a future problem. It is a now problem. To stand a chance of limiting global warming to 1.5℃, we have 8 years to almost halve greenhouse gas emissions: 8 years to make the plans, put in place the policies, carry them out and deliver the cuts. The clock is ticking loudly.”
Emissions fell by about 5. 4% last year during Covid lockdowns, the report found, but only about one-fifth of the economic recovery spending goes towards reducing carbon emissions. This failure to “build back better”, despite promises by governments around the world, cast doubt on the world’s willingness to make the economic shift necessary to settle the climate crisis, the UN said.
In the run-up to COP26, countries were supposed to submit (递交) national plans to cut emissions—called nationally determined contributions (NDCs) —for the next decade, a requirement under the 2015 Paris climate agreement. But the UNEP report found only half of countries had submitted new NDCs, and some governments had presented weak plans.
1. Why were the findings described as a “thundering wake-up call” in Para. 2?| A．Because the world has failed to live up to its current commitments. |
| B．Because the opportunities presented by covid-19 have been wasted. |
| C．Because the world is falling behind in slowing down temperature rises. |
| D．Because the serious problems were brought about by global fossil fuels. |
| A．current commitments of many countries remain unchanged |
| B．huge gaps are bridged between previous and present proposals |
| C．global sustainable environmental resources develops significantly |
| D．strict measures are taken to reduce emissions in the coming ten years |
| A．To show the number of alarm clocks required. |
| B．To explain the reason for the world’s wasting chances. |
| C．To ask for the number of the countries attending the meeting. |
| D．To stress the need to make the most of resources and reduce emissions. |
| A．Few countries have submitted plans to reduce the emissions. |
| B．Many countries’ plans to cut emissions are far from satisfactory. |
| C．Most of the countries work under the Paris Climate Agreement. |
| D．Much progress in reducing emissions has been made these years. |
