1 . Animals, including humans, feel sound as well as hear it, and some of the most meaningful communication happens at frequencies (频率) that people can’t hear. Elephants, for example, use these low-frequency sounds to, among other things, find family or a mate across long distances. Whales do it, too.
But you don’t have to weigh a ton to make a sound. In fact, you don’t have to be bigger than a pea. Consider, for example, the tree-hopper, a curious little animal that lives on the stems (茎) of the leaves. University of Missouri biologist Rex Cocroft has spent much of his time listening closely to tree-hoppers with his team.
The team discovers that all the sounds being heard from tree-hoppers are produced by males. They do it by vibrating (振动) their abdomens (腹部) to make a wide variety of strange sounds. There is almost no airborne sound produced with these vibrational sounds. Cocroft explained, “If a tree-hopper were to stand on your finger and produce a sound, you would feel the vibration but hear no sound.”
They showed that some sounds, not surprisingly, seem to be aimed at attracting females. And some are aimed at other males.
Cocroft explained, “When two males meet each other, or when they are mate-searching on a branch, we’re hearing ‘purring, bdddddrrrr…’ sounds that males give.” Normally, a person couldn’t hear any of this, because the sound travels along the stem, inside it. And that’s how other tree-hoppers detect it.
Cocroft said tree-hoppers have very sensitive legs. And they stand around on stems, which are good at spreading vibrations. So they just use what nature gives them to communicate with each other.
“They have so many different forms of social behavior and grouping,” Cocroft explained. “And once there are animals living in groups, then there will be all sorts of interesting possibilities for communication.”
1. What does Cocroft’s research focus on about tree-hoppers?| A．Their variety. | B．Their communication. |
| C．Their living areas. | D．Their numbers. |
| A．They sense sounds by legs. |
| B．They knock the stems to make sounds. |
| C．Their sounds can be easily heard by humans. |
| D．Females make sounds to meet each other |
| A．It is key to their survival. |
| B．It drives an increase in their numbers. |
| C．It often leads to communication. |
| D．It contributes much to the division of animal types. |
| A．A Magic Moment in Nature | B．A Journey to the Wildlife |
| C．Learning From Nature | D．Communication Sounds Among Animals |
2 . Every year the start of the Atlantic hurricane season is another reminder for Margarite August that she still doesn’t have a roof.
The 70-year-old retired teacher’s home on the small Caribbean island nation of Dominica was mostly wiped out by hurricane Maria six years ago.
Six years after hurricane Maria, Dominicans like Margarite August still haven’t been able to rehabilitate their homes.
August is not alone. Since Maria, the government of Dominica has built 7,000 new homes—about a quarter of its housing stock-with materials to fight another Category 5 hurricane. They’ve also relocated two communities. But an untold number of the island’s 70,000 or so residents are like August, rebuilding their homes in any way they can afford.
Hurricane Maria is often referred to as a once-in-a-lifetime disaster. Scientists put much of the blame on warming ocean temperatures that could make frequent (频繁的) storms like it.
Maria damaged a terrible 95% of Dominica’s housing stock and 226% of the nation’s GDP. Before the storm, the country’s economy had long struggled since its independence from Great Britain in 1978. Unlike its more famous touristy neighbors along the chain of eastern Caribbean islands it lies on, Dominica is more known for its rugged mountains and jungles (丛林) than white sandy beaches.
The jungle mountains that crash down to the coast are beautiful but disasters visit easily. “I don’t think anybody ever got over Maria,” says Christine John of the Dominica Red Cross. “There are a lot of persons today—if it just starts to rain outside, they get anxious.”
1. What does the underlined word “rehabilitate” in paragraph 3 mean?| A．Rebuild. | B．Leave. | C．Decorate. | D．Buy. |
| A．Over-farming. | B．Loss of the land. |
| C．The disappearance of the forests. | D．Climate change. |
| A．Its good economy. | B．Its architecture. |
| C．Its mountains and jungles. | D．Its sandy beaches. |
| A．They have to stay bored at home. | B．Their houses are easy to take in water. |
| C．They don’t know how to make umbrellas. | D．They are afraid of another disaster like Maria. |
3 . Cancer-fighting genes in elephants could help tackle one of the biggest killers of people, according to research. Despite their large bodies and long lifespans, elephants are much less likely to die from cancer than humans, with death rates of less than 5 percent.
The paradox has puzzled scientists because more cells lead to greater replications (复制), which increases the possibility of the body failing to detect damaged DNA or a faulty cell that can result in tumors(肿瘤). Elephants live for almost as long as humans and weigh up to five tons.
However, a group of British and European scientists say they have taken a big step towards solving Peto’s paradox, named after the British epidemiologist Sir Richard Peto. Elephants, they say, carry a much larger more diverse group of tumor-fighting proteins.
The findings, published last week in the journal Molecular Biology and Evolution, raise hopes that the cancer fighting genes in elephants could be the key to tackling cancer, which kills about 167, 000 Britons yearly. Cells keep dividing throughout an organism’s life, each carrying the risk of producing a tumor. One of the body’s weapons is a gene called p53 known as the “guardian of the genome”, which hunts cells with faulty DNA. It encourages the cell to repair itself or self-destruct, keeping the cell from combining with others and producing tumors.
Humans have two versions of p53 but elephants have 40, said the researchers. Biochemical analysis and computer simulations also showed that an elephant’s p53 genes are structurally slightly different, providing a much larger anti-cancer toolkit. The researchers suspect that while faulty cells might be able to skirt two p53 versions, they cannot combine with other cells as easily in the face of dozens.
The findings will open the way for research on how p53 genes of elephants are activated and on medical treatment for humans.
1. What has puzzled scientists?| A．Few elephants end up dying from cancer. | B．Elephants live long and weigh enormously. |
| C．More cells lead to higher chances of tumors. | D．A larger body is less likely to discover faulty cells. |
| A．How many Britons die each year. | B．How the anti-cancer gene works. |
| C．How the research was carried out. | D．What the findings have been applied to. |
| A．Strengthen. | B．Detect. | C．Escaped. | D．Cure. |
| A．Scientists find elephants live longer than humans. | B．P53 genes play essential role in preventing cancer. |
| C．Elephant genes could be key to fighting cancer. | D．Groundbreaking treatment for cancer is on the way. |
One sunny Saturday morning, I got ready for a hike with my classmates. I was so excited about it since it was my first time to go hiking. I ate a light breakfast just a few slices of bread and an egg. After that I grabbed my backpack and hurriedly ran out of my house and then met my classmates at the school gate. At that time I didn’t think that there would be a terrible disaster ahead.
The jungle (丛林) that we are going to was far from our area. Its name was Salymbia Jungle. The drive was 3 hours long but it was not a dull ride as we were all eager about the hike and we bad each other’s company. We appointed a guide and his name was Thomas. He said that he had hiked in the Salymbia Jungle lots of times, and he was familiar with the pathways. When we arrived, Thomas allowed us to begin. There were a wide variety of plants which I had never seen before. The smell of the jungle was so earthy. All of us were amazed by the beauty of the scenery and the sound of the creatures.
After a while we were walking and then I looked at my wrist (手腕) to check the time but then I realized my watch had fallen off. Then I walked back without telling anyone. I did not worry about getting lost since there were other persons behind and I thought I would have been able to catch up with my classmates. I went back searching the pathway and I lost track of time and lost sight of my classmates. I immediately realized that I was alone.
After I realized I was lost, the first thing I did was to check my phone to see how far away I was from my companions. However, I was having no luck because there was no network in my phone, which made my phone practically useless.
Paragraph 1: The sky started to become darker.___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Paragraph 2: As I was falling asleep, I heard a human voice.
___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
5 . In the office of remote sensing scientist Liu Shaochuang, there is a huge photograph of a camel he snapped a decade ago in Xinjiang. He crouched for hours by a pool of water in the Gobi Desert to capture the image.
Since 2012, he has led a team in tracking and studying wild camels using satellite remote sensing technology.
Unlike zoologists who focus on species, Liu has studied the interrelationship between endangered animals and their environment, which he believes will help develop better protection strategies in the face of climate change.
His interest in wild camels began when his team tested a prototype(雏形)design of the lunar rover Yutu in the desert. Living in the harsh deserts in northwestern China and southwestern Mongolia, camels are listed as critically endangered animals. Experts estimate that the population of this species is currently less than 1, 000, of which around 650 are in China.
“Ten years ago, the research relied solely on human observation, which was very primitive, ”Liu says. Because camels are fully migratory and can travel over long distances, scientists used to learn their habits by studying hoof prints and droppings. It was hard to find one camel in the desert, let alone track it. But Liu thought his expertise in satellite navigation(导航)and remote sensing might come in useful in the study of wild camels.
It was not easy at first. Liu learned zoology from scratch. His team had to spend several weeks each year braving dust and sandstorms in the vastness of the Gobi Desert seeking out camels. A scar on his right eyebrow is the result of a rollover accident on a rugged mountain road in Xinjiang.
“The most exciting moment was attaching a satellite positioning collar to a wild camel. ”The tracking collar, equipped with special receivers, weighs only a few hundred grams. It can detach automatically and will not have a negative impact on the daily lives of the animals. The locations of the tracked animals are transmitted via satellite every day. Based on the data, scientists can get to know their migratory paths, living environments and possible threats they may meet with.
For Liu, it is worth the significant sci-tech effort to study such a rare species. He adds wildlife protection and research will become more precise and efficient with the help of technology.
1. What was it that made tracking wild camels difficult?| A．The number of camels experienced a sharp decline. |
| B．Massive migration made camels cover huge distances. |
| C．Primitive tools were used in human observation. |
| D．Hoof prints and droppings were never to be seen. |
| A．His carelessness in carrying out his research. |
| B．His inexperience at the very beginning of his work. |
| C．The rough conditions under which he worked. |
| D．The stress he met with in his work. |
| A．The formation of the tracking collar. |
| B．The definition of the tracking collar. |
| C．The importance of the tracking collar. |
| D．The function of the tracking collar. |
| A．Generous and ambitious. | B．Confident and grateful. |
| C．Creative and determined. | D．Optimistic and modest. |
6 . What if someone told you about a kind of grass as tall as the tallest trees? A grass as strong as steel? Would you believe that person? You should, for that grass is bamboo (竹子), which has more than 1,000 uses. It is not just a material for making useful products. Young bamboo is eaten, often mixed with other vegetables.
Bamboo grows in many parts of the world. In the USA it grows in many states like Virginia and Florida. Most bamboo, however, is found in wet and warm climates, especially in Asia and on the islands of the South Pacific Ocean.
In most Asian countries, bamboo is nearly as important as rice. This unusual material is used to not only build large buildings but also make water pipes, musical instruments and paper. There are over 1,000 kinds of bamboo. No wonder the lives of nearly half the people on earth would change greatly if there were no longer any bamboo.
1. According to the text, bamboo is actually a kind of .| A．grass | B．steel | C．tree | D．vegetable |
| A．Only in Asia. | B．Only in the USA. |
| C．In wet and warm climates. | D．All over the world. |
| A．Build large buildings. | B．Make water pipes. |
| C．Make musical instruments and paper. | D．All of the above. |
| A．Over 1,000. | B．Over 800. | C．Over 600. | D．Over 400. |
7 . Kids everywhere love to play. And they know a ball is a perfect thing to play with. Now scientists at London’s Queen Mary University report that bumblebees seem to know the same thing, making bumblebees the first insects known to play.
When people talk about “play”, they’re describing an animal doing something that doesn’t really seem to help it. They’re not doing the action to get food or shelter or another similar “reward”. Play usually happens when a creature is relaxed and is often repeated.
However, scientists think many animals and birds’ playing is a kind of training for things they’ll have to deal with in later life. But before this, there were no reports of insects playing.
Scientists at Dr. Chittka’s lab, carried out an experiment. First, they tagged (贴标签) 45 young bumblebees, both male and female, between 1 and 23 days old. The tags made the bees easier to identify and follow.
The scientists set up a clear pathway from the bumblebees’ nest to a feeding area. On either side of the open pathway, the researchers placed small colored wooden balls. On one side of the path, the balls were attached and couldn’t move. On the other side, the balls could roll around. It turned out that the bumblebees weren’t interested in the unmovable balls, but they made lots of visits to the rolling balls.
Grabbing the balls with their legs, the bees would flap (拍打) their wings to pull on the balls, causing them to roll. The 45 tagged bumblebees rolled balls 910 times during the experiment. Though some only did it once, others did it a lot. The younger bumblebees spent more time rolling balls. Males seemed more likely to play than females.
“It’s not clear why the bees roll the balls or whether they enjoy it But the experiment raises important questions about how the insects’ minds work and whether they have feelings. With further research, the future will hold surprises and answers in store for us,” said Dr. Chittka.
1. What is the purpose of animals’ play according to scientists?| A．To find ideal shelter. |
| B．To receive extra rewards. |
| C．To develop survival skills. |
| D．To get their fellows’ attention. |
| A．Bumblebees’ categories. | B．Bumblebees’ habitats. |
| C．Bumblebees’ intelligence. | D．Bumblebees’ behavior. |
| A．Younger male bumblebees preferred to roll the balls. |
| B．Bumblebees possessed different wing beat frequency. |
| C．Bumblebees could distinguish balls of different colors. |
| D．A specially-built pathway helped bumblebees find food. |
| A．Uncertain. | B．Doubtful. | C．Optimistic. | D．Critical. |
8 . There is hot, and then there is hot! Extreme heat is a period of high heat and humidity with temperatures above 90 degrees Fahrenheit for at least two to three days. Extreme heat is responsible for the highest number of annual deaths among all weather-related hazards (危害).
It’s not your imagination. Summers have been getting hotter and hotter with extreme heatwaves occurring earlier and more frequently. But why is this happening and can we better predict heatwaves in advance to give people time to prepare?
“Climate change is here and it’s already been changing human behavior and causing significant influence in the society. As global temperatures rise, historically excessive (过高的) temperatures are more likely to occur.” says Craig Ramseyer, an assistant professor who studies climate modeling in the department of geography at Virginia Tech.
Ramseyer says heatwaves are the most concerning because of the lack of attention they normally receive. “Hurricanes, tornadoes, and flash floods drive more media attention because of the natural attraction with the visual impact of those types of hazards. However, heat does not tend to be as attractive and it becomes very difficult to communicate the danger to the public,” said Ramseyer. “Around the world, more deaths occur due to extreme heat than from hurricanes, flooding, and drought combined. It impacts the most helpless of our citizens who do not have enough access to air conditioning, water, and other important resources.”
Since the Earth is running warmer than it used to, Ramseyer says that when these heatwave-related weather patterns take place, it results in higher extreme temperatures than we used to experience 30 years ago.
“As a global community, we need to decrease carbon emissions as soon as possible. We have rapidly developing technologies that are going to help advance the process, but the faster the better, there is no time to waste.”
1. What can we learn from the article?| A．Extreme heat is a No.1 death cause. |
| B．People are suffering more extreme heat. |
| C．A 100-degree heat is an extreme heat. |
| D．Extreme heat is getting better over the years. |
| A．Climate change will soon affect human behaviors. |
| B．High temperatures happened frequently in history. |
| C．Air conditioning and water can stop the extreme heat. |
| D．Garbage sorting can less advance the climate change. |
| A．Extreme heat can be stopped by technology. |
| B．People have enough time to solve the climate problems. |
| C．The danger of extreme heat is not easily transferred to the public. |
| D．Heatwave-related weather patterns will decrease in the future. |
| A．Complaints about extreme heat. | B．Prevention of extreme heat. |
| C．Characters of extreme heat. | D．Technologies behind extreme heat. |
9 . Antarctic blue whales have been perceived again in the sub-Antarctic island of South Georgia. An international-team of researchers discovered the animals five decades after whaling (捕鲸业) nearly caused them to disappear forever. “The ocean resources at South Georgia were heavily developed during the early 20th-century industrial whaling,” says lead author Susannah Calderan, an ecologist with the Scottish Association for Marine Science.
Antarctic blue whales were plentiful in the area until whaling began there in 1904, kicking off the beginning of industrial whaling in the Southern Ocean. While hunters originally focused on species that could be easily caught, like the humpback whale, the focus quickly moved to the blue whale. Between 1904 and 1973, 345,775 Antarctic blue whales were killed in the Southern hemisphere (半球）and in the northern Indian Ocean. Around South Georgia, blue whale catches were reported year-round without stopping. Between 1904 and 1971, industrial whaling caused 42, 698 blue whales’ death, Blue whales almost disappeared in these areas.
Researchers studied all Antarctic blue whale data from the last three decades. They examined sightings (目睹)from scientific surveys collected by observers on ships, as well as opportunistic sightings reported by seamen and ship passengers to the South Georgia. They also examined acoustic(声音的）recordings of blue whale.
They found that whale surveys from ships off South Georgia resulted in just one blue whale sighting between 1998 and 2018. But more recent surveys suggest better news. A survey in February of 2020 found nearly 60 blue whale sightings, and several acoustic detections (探测).A total of 41 blue whales have been recognized through photos from South Georgia between 2011 and 2020.
“Their return is very meaningful, as it was widely thought that blue whales at South Georgia might have been hunted beyond a point where they could recover, and might never be seen again in great numbers at South Georgia,” Calderan says. “Our research shows that, populations can recover even from very low levels if they’re given enough protection.”
1. What does the underlined word “perceived” in paragraph 1 mean?| A．Kept. | B．Found. | C．Hunted. | D．Destroyed. |
| A．The development of industrial whaling. |
| B．The cause of blue whales’ disappearance. |
| C．The wide spread of blue whales in the past. |
| D．The tricks of catching blue whales easily. |
| A．There is an increasing return of blue whales. |
| B．Blue whales are in a more dangerous situation. |
| C．More and more people like watching blue whales. |
| D．South Georgia is a good place to watch blue whales. |
| A．The risk of killing whales at higher rates. |
| B．The sign of Antarctic blue whales’ return. |
| C．The way of protecting Antarctic blue whales. |
| D．The effect of the great loss of ocean resources. |
10 . China is one of the countries with the most serious natural disasters in the world. There are many kinds of disasters, with wide distribution, high frequency and heavy losses. In the background of global climate change, major natural disasters occur from time to time.
Fire
When a fire breaks out, smoke threatens mostly.
Mud-rock flow
Rainstorm may cause mud-rock flow, an it’s really dangerous to stay downstream. When you try to escape from it, instead of going along the bottom of the ditch, it is much wiser to climb up the mountain horizontally quickly. Please escape from ditch when selecting camping field. It’s important to check the weather when going into the mountain
Flood
Lightning strike
On cloudy and rainy days, a lightning strike may happen.
| A．Cut off the power and shut off water sources. |
| B．Please don’t stand under the tree in such kind of weather. |
| C．Try to find a higher place, but staying on a roof isn’t a good choice. |
| D．First you need to take shelter, then find a gap under the table or bed. |
| E．Losses caused by natural disaster in China are continuously increasing. |
| F．They also play a part in popularizing the knowledge and self-rescue skills. |
| G．In that case, please cover your nose and your mouth with a wet towel. |
