1 . People have been wondering why elephants do not develop cancer even though they have lifespans(寿命)that are similar to humans, living for around 50 to 70 years.
Now scientists believe they know why. A team at the University of Chicago, US has found that elephants carry a large number of genes that stop tumors(肿瘤)developing. To be precise, they found 20 copies of an anti-tumor gene called TP53 in elephants. Most other species, including humans, only carry one copy.
According to the research, the extra copies of the gene improved the animal’s sensitivity to DNA damage, which lets the cells quickly kill themselves when damaged before they can go on to form deadly tumors.
“An increased risk of developing cancer has stood in the way of the evolution of large body sizes in many animals,” the study author Dr Vincent Lynch told The Guardian. If every living cell has the same chance of becoming cancerous(癌变的),large creatures with a long lifespan like whales and elephants should have a greater risk of developing cancer than humans and mice. But across species, the risk of cancer does not show a connection with body mass.
This phenomenon was found by Oxford University scientist Richard Peto in the 1970s and later named “Peto’s paradox(悖论)”. Biologists believe it results from larger animals using protection that many smaller animals do not. In the elephant’s case, the making of TP53 is nature’s way of keeping this species alive.
The study also found that when the same genes were brought to life in mice, they had the same cancer resistance as elephants. This means researchers could use the discovery to develop new treatments that can help stop cancers spreading or even developing in the first place.
“Nature has already figured out how to prevent cancer,” said Joshua Schiffman, a biologist at the School of Medicine, University of Utah, US. “It’s up to us to learn how different animals deal with the problem so that we can use those strategies to prevent cancer in people.”
1. Why are elephants unlikely to develop cancer?| A．Certain genes in their body kill existing tumors. |
| B．They have a rather large body size. |
| C．They carry many genes to prevent tumors developing. |
| D．Their genes suffer no DNA damage. |
| A．The huge body mass. |
| B．Deadly tumors. |
| C．Cells killing themselves. |
| D．Sensitivity to DNA damage. |
| A．The risk of cancer is not related to body size. |
| B．Larger animals have protection from TP53. |
| C．Larger animals suffer the same risk of cancer as smaller ones. |
| D．The larger animals are, the bigger risk of cancer they will have. |
| A．Depending on nature is surely enough to fight against cancer. |
| B．The TP53 genes have proved useful in stopping cancer in people. |
| C．The extra copies of elephants’ genes are used to cure cancer patients. |
| D．Humans are expected to prevent cancer with the making of TP53. |
2 . Fire ants are famous for their construction projects (as well as their burning bites). When they need to, colonies of these insects turn themselves into ladders, chains and walls. And when flood water rises, a colony can float to safety by making an unusual boat. The ants hold tightly to each other, forming a floating disk atop the water. The antraft may float for months seeking safe harbor. The ants on the bottom don’t drown, and the ants on the top stay dry. Working together, the ants float to safety — even though a single ant alone in the water will struggle to survive.
“They have to stay together as a colony to survive.” Nathan Mlot said.
Fire ants and water don’t mix. The ant’s hard outer shell, naturally repels water. A drop of water can sit on top of the ant like a backpack. When an ant does end up underwater, tiny hairs on its body can trap bubbles of air that give the bug a boost up.
To investigate the science behind the antraft, the scientists placed hundreds or thousands of ants at a time in the water. A group of ants took about 100 seconds, on average, to build a raft. The researchers repeated the experiment multiple times. Each time, the ants organized themselves the same way, creating a raft about the size and the thickness of a thin pancake. The rafts were flexible and strong, staying together even when the researchers pushed the rafts underwater.
The scientists then froze the rafts in liquid nitrogen and studied them under powerful microscopes to figure out how the ants kept everyone safe and the water out.
The team found that some ants used their jaws to bite other ants’ legs. Other ants joined their legs together. Thanks to these tight bonds, say the scientists, the ants did a better job at keeping the water away than any one ant could do on its own. By working together, thousands of ants can stay alive in the face of a crisis like a flood by using their own bodies to build a boat.
1. When flood comes, fire ants ________.| A．will run away separately | B．find a hole to hide themselves |
| C．combine themselves into a raft | D．climb onto boats on the water |
| A．Tiny hairs on their body. | B．Their hard outer shell. |
| C．Their slippery skin. | D．Their backpack on its body top. |
| A．built a raft in 100 minutes | B．organized themselves into a flexible raft |
| C．organized themselves in different ways | D．liked to look for the food of pancakes |
| A．practice | B．calmness | C．cooperation | D．speed |
| A．how fire ants react in face of danger | B．fire ants’ differences from common ants |
| C．fire ants’ ability to live underwater | D．the building ability of fire ants |
3 . Animals might not be able to speak or master advanced language techniques, but they certainly have other ways of communicating. Whale song, wolf howls, frog cries — even the fast dance of the honeybee or the friendly waves of a dog’s tail — are among so many ways animals pass on information to each other and to other living things of the animal kingdom.
When it comes to hearing communication, not every member of a species is just alike. Animals in different places have often been sounding off in different dialects. For example, one study shows that blue whales produce different types of sounds depending on where they are from. Some bird species are the same way. And what about those birds that live on the border between territories (领地) of different songbirds? They are often able to communicate in a way accepted by each of their groups of neighbors.
Communication between different species can play important roles as well. One study shows that iguanas (鬣蜥蜴) do not communicate by making sound, but their well-developed ears help them hear well the warning calls of the flycatcher (a type of small bird). The two species have nothing in common except for the fact that they share a general habitat and enemies. So when an iguana hears a bird make a signal of danger for other birds, it probably knows to be watchful for arriving enemies, too.
However, as noise pollution has become a serious problem all across the globe, many animals are now under fire. Increased shipping traffic over the last century has greatly affected the spread of whale song around the ocean basin. Studies have found that songbirds, too, suffer from noisy city surroundings. Some species have had to change their singing styles, producing songs that sound louder, in order to be heard above the noise. Their new voices usually lead to stranger and somewhat worse styles of singing that female birds find decidedly less sexy.
1. What does the author mainly tell us in Paragraph 2?| A．Various dialects can also happen to the same animals. |
| B．Animals communicate with each other in different ways. |
| C．Different animals have different ways of communicating. |
| D．Animals from different places may make the same sound. |
| A．They communicate by singing. |
| B．They are born with poor hearing. |
| C．They often bring bad luck to humans. |
| D．They get along well with flycatchers. |
| A．they refuse to communicate with others |
| B．they cannot communicate effectively |
| C．they are now in danger of dying out |
| D．they don’t make a sound any more |
| A．find it hard to attract the opposite sex |
| B．produce more songs that sound sad |
| C．begin to communicate by dancing |
| D．can not find food easily any more |
| A．by raising questions |
| B．by following time order |
| C．by providing examples |
| D．by analyzing the data |
4 . In France, it is the end of an era. The country used to consider training captive animals to delight humans acceptable. Last month, however, it banned the capture and captive breeding of marine mammals, which include dolphins and orcas. Thus, marine circuses in France will be phased out. The French Environment Minister, Ségolène Royal, cited animal welfare in the decision. She reported that some animals were mistreated in aquariums.
This decision is taking place in a global context of changing attitudes. For decades, marine circuses amazed people with the sight and sound of orcas. These are beautiful and intelligent animals. Marine circuses can be entertaining, and they can educate and inspire awe. Children especially can be taught the value of animals first-hand by seeing their power and majesty (壮丽). However, marine circuses make animals perform in a tank, and even a large tank is not a natural environment for orcas.
This contradiction is best shown in the tragic case of the American trainer Dawn Brancheau. She always felt a strong connection to animals. No doubt she respected them. She was inspired to become an orca trainer by a vacation to SeaWorld Orlando. However, she was ultimately killed by an orca named Tilikum during her show at the same circus in 2010. This was not an isolated case. Captive orcas have often harmed people, and poor Tilikum had been involved in two deaths before. In recent years, a global movement has blamed such incidents on captivity itself. In 2013, a powerful documentary, Blackfish, argued that captivity is distressing for orcas. Public opinion is shifting. By 2016, SeaWorld began to phase out orca breeding and performances.
Royal is famous in France for her concern for children’s development. I trust she has thought carefully about what aquariums could achieve. We must teach children about nature, but that should include respect for animals. In your lives, you can make a difference every time you go to a zoo or an aquarium. Study the animals and their natural environment. Based on what you’ve learned, do you think the animals are healthy and happy? This is how you develop moral maturity. As a mature species, we recognize animal rights. We can learn about our fellow creatures without capturing them.
1. The author was prompted to write this article by ____.| A．the tragic case of the American trainer Dawn Brancheau |
| B．Blackfish, a 2013 documentary |
| C．France’s decision to ban the capture and captive breeding of marine mammals |
| D．SeaWorld’s decision to phase out orca breeding and performances |
| A．disappeared | B．forbidden | C．enhanced | D．dismissed |
| A．people can hardly be delighted by the majesty of marine mammals any longer |
| B．aquariums can hardly help children study animals and their natural environment |
| C．many tragic cases took place in aquariums in recent years |
| D．some marine mammals are mistreated in aquariums |
| A．We must ensure that we don’t deny animals their rights while we learn about them. |
| B．More children should be brought to aquariums to learn about marine animals first-hand. |
| C．Most animals living in zoos and aquariums can enjoy healthy and happy lives. |
| D．Ségolène Royal failed to take children’s development into consideration as she banned the capture and captive breeding of marine animals in French aquariums. |
5 . Priscilla Ouchida’s “energy efficient” house turned out to be a horrible dream. When she and her engineer husband married a few years ago, they built a $100,000 three-bedroom home in California. Tightly sealed to prevent air leaks, the house was equipped with small double-paned windows and several other energy-saving features. Problems began as soon as the couple moved in, however. Priscilla’s eyes burned. Her throat was constantly dry. She suffered from headaches and could hardly sleep. It was as though she had suddenly developed a strange illness.
Experts finally traced the cause of her illness. The level of formaldehyde gas in her kitchen was twice the maximum allowed by federal standards for chemical workers. The source of the gas? Her new kitchen cabinets and wall-to-wall carpeting.
The Ouchidas are victims of indoor air pollution, which is not given sufficient attention partly because of the nation’s drive to save energy. The problem itself isn’t new. “The indoor environment was dirty long before energy conservation came along,” says Moschandreas, a pollution scientist at Geomet Technologies in Maryland. “Energy conservation has tended to accentuate the situation in some cases.”
The problem appears to be more troublesome in newly constructed homes rather than old ones. Back in the days when energy was cheap, home builders didn’t worry much about unsealed cracks. Because of such leaks, the air in an average home was replaced by fresh outdoor air about once an hour. As a result, the pollutants generated in most households seldom built up to dangerous levels.
1. It can be learned from the passage that the Ouchidas’ house ________.| A．is well worth the money spent on its construction |
| B．is almost faultless from the point of energy conservation |
| C．failed to meet energy conservation standards |
| D．was designed and constructed in a scientific way |
| A．Poor quality of the air inside. | B．Poor quality of the construction. |
| C．Gas leakage in the kitchen. | D．The newly painted walls. |
| A．relieve | B．accelerate | C．worsen | D．improve |
| A．Because indoor cleanliness was not emphasized. |
| B．Because energy used to be inexpensive. |
| C．Because environmental protection was given top priority. |
| D．Because they were technically unavoidable. |
| A．Energy Conservation | B．House Building Crisis |
| C．Air Pollution Indoors | D．Traps in Building Construction |
6 . My wife and I moved into our home nine years ago. We have a yard a “rock garden”. There the rocks appear to be just thrown up onto the dirt as if someone were in a hurry to finish. Very often when we have more flowers, Denise or I would plant them between the rocks, just to bring some color to the area.
Last summer I found, in the rock garden, a tiny little plant that I could not immediately recognize. I knew I didn’t plant it and Denise said she didn’t either. We decided to let it continue growing until we could find out what it was.
Weeks passed and as I made my way back to the strange plant, it appeared to be a sunflower. It looked thin and tall with only one head on it. I decided to baby it along and weed (除草) around it. As I pulled rocks from the area to get to the weeds, I noticed something unusual. The sunflower had not started where I saw it begin. It actually had begun under a big rock and grown under and around it to reach the sun.
If a tiny little sunflower didn’t let a big rock stand in its way of developing, we too have the ability to do the same thing. If we believe in ourselves like that little sunflower, we can reach where we aim to go and get what we need for growth.
We need to believe in ourselves knowing we have the ability to achieve our goals. Like the sunflower, it knew it had the ability to get over the rocks because it had faith in itself that it would succeed. Stand tall like the sunflower and be proud of who and what we are, then other things will begin to support us. We will find a way to go under or around any “rocks” in order to realize our goals.
1. The family planted flowers in the yard ________.| A．to attract visitors | B．to remove the rocks |
| C．to please their neighbors | D．to make the area colorful |
| A．to see how long it could live | B．to see how big it could grow |
| C．to find out what it actually was | D．to know if his wife had planted it |
| A．it was very thin and tall | B．it had only one head on it |
| C．it grew on top of a big rock | D．it began to grow under a rock |
| A．rocks cannot prevent us from success |
| B．we can get over difficulties if we trust ourselves |
| C．we should take good care of the rock gardens |
| D．sunflowers are able to grow everywhere |
| A．Stand Tall Like the Sunflower | B．The Sunflower and My Family |
| C．Being Proud of the Sunflower | D．The Secret of the Sunflower |
| A．Sunny. | B．Rainy. | C．Cloudy. |
8 . Plants cannot run or hide, so they need other strategies to avoid being eaten. Some curl up their leaves, others produce chemicals to make themselves taste bad if they sense animals drooling on them, chewing them up or laying eggs on them—all signals of an attack. New research now shows some flora can feel a plant-eating animal well before it launches an attack, letting a plant prepare a preemptive（先发制人的）defense that even works against other pest species.
When ecologist John Orrock of the University of Wisconsin-Madison sprayed snail slime—a liquid the animals release as they slide along—onto soil, nearby tomato plants appeared to notice. They increased their levels of an enzyme（酶）, which is known to prevent plant-eating animals. “None of the plants were ever actually attacked,” Orrock says. “We just gave them cues that suggested an attack was coming, and that was enough to cause big changes in their chemistry.”
Initially Orrock found this defense worked against snails; in the latest study, his team measured the slimy warning’s impact on another potential threat. The investigators found that hungry caterpillars（毛虫）, which usually eat tomato leaves greedily, had no appetite for them after the plants were exposed to snail slime and activated their chemical resistance. This nonspecific defense may be a strategy that benefits the plants by further improving their overall possibilities of survival, says Orrock, who reported the results with his colleagues in March in Oecologia.
The finding that a snail’s approach can cause a plant response that affects a different animal made Richard Karban curious, a plant communications expert, who was not involved in the study. “It is significant that the plants are responding before being damaged and that these cues are having such far-ranging effects, ” Karban says. The research was comprehensive, he adds, but he wonders how the tomato plants felt chemicals in snail slime that never actually touched them.
“That’s the million-dollar question,” Orrock says. He hopes future research will make out the mechanisms that enable plants to sense these relatively distant cues.
1. John Orrock sprayed a liquid onto soil near tomato plants to ________.| A．make them grow better |
| B．give them a warning |
| C．keep plant-eating animals away |
| D．inform plant-eating animals of danger |
| A．To introduce another animal. |
| B．To confirm the result of the study. |
| C．To appeal to people to protect animals. |
| D．To analyze different resistance chemicals. |
| A．How tomato plants become aware of danger. |
| B．What the chemicals in the snail slime are. |
| C．Whether the research is of practical value. |
| D．What the finding of the research is. |
| A．Watchful Plants. | B．Greedy Animals. |
| C．A Snail’s Approach. | D．A Defense Attack. |
9 . Wind power is a very clean source of energy. This is how wind power works. Wind makes windmills spin(旋转). When the windmills spin, they make electricity. Then we can use the electricity.
A lot of people think that wind power is new, but that’s not true. For thousands of years, people have used wind to sail boats and move water. We still do those things today, but these days we mostly use wind power to make electricity.
Wind power is a very popular source of energy. Most people think that we should use it more and more. First of all, it’s clean. Windmills don’t pollute the environment at all. Second, we can use wind power forever. After all, we will always have wind. Also, wind power is cheap, and it’s getting even cheaper.
A lot of people don’t understand wind power very well. They believe that there are problems with wind power, but many of those problems are not real. For example, some people say that windmills are dangerous for birds. They used to be true, but it isn’t true anymore. Old windmills killed birds because they spun very fast. New windmills spin slowly, and they aren’t dangerous for birds.
However, there are real problems with windmills. One problem is that many people think windmills are very ugly. This is a problem for people, because windmills are often in very pretty areas. Also, wind doesn’t blow all the time, so we can’t use wind power all the time. Finally, windmills are noisy.
Wind power is becoming more and more common. Right now, more than 80 countries use wind power. About 2.5 percent of the world’s power comes from the wind. For some countries, that number is a lot higher. Wind power gives Denmark more than 25 percent of its electricity.
1. Why DON’T new windmills kill birds? Because ________.| A．birds don’t fly near them | B．they are shorter than old windmills |
| C．they spin slowly | D．new windmills don’t spin |
| A．Over 1,000 years ago. | B．About 500 years ago. |
| C．About 80 years ago. | D．About 25 years ago. |
| A．We can’t use windmills at night |
| B．Windmills break all the time |
| C．Wind doesn’t blow all the time |
| D．Windmills are too expensive to use all the time |
| A．Most people don’t like it. | B．Denmark doesn’t use it. |
| C．It’s getting more expensive. | D．It’s getting cheaper. |
| A．Dangerous Birds | B．Popular and Clean Wind Power |
| C．Cheap and Clean Energy | D．Expensive Windmills |
10 . Ask people to name the world's tallest peak and anybody with sound general knowledge will name Mount Qomolangma. But quiz them on its exact height and many will hesitate. Recently, a team of over 30 Chinese surveyors left the base camp at Mount Qomolangma for a higher spot on its journey to the peak on Wednesday as part of the country's mission to remeasure the height of the world's highest mountain.
The remeasurement of the peak's height is a part of China's latest large-scale scientific survey of Qomolangma. Preparation of the project was started in early March, with 53 surveyors from the First Geodetic Surveying Brigade (大地测量旅) getting stationed near Qomolangma to carry out adaptive climbing and training in other technical skills, and they are going to the survey on the top of the mountain.
To ensure the accuracy of the measurement, and to work it in a more scientific way, experts from the Chinese Academy of Surveying and Mapping, the Shaanxi Bureau of Surveying, and the China Geological Survey were invited to assist in the technical design and planning of the project from the beginning.
The technical innovation and breakthrough applied in the latest survey include the application of the BeiDou-3 Navigation Satellite System and advanced domestic surveying and mapping instruments.
The Chinese government has conducted six large-scale surveys and measurements on Qomolangma in the past few decades; it had successfully measured and announced the height of the mountain in 1975 and 2005. Chinese mountaineers and researchers climbed Mount Qomolangma in 1975 to determine its height and concluded that the rock height of the peak was about 8,848.13 meters; in 2005, the summit measured 8,844.43 meters. It is believed that this remeasurement will surely bring about surprise to the world, thus showing how powerful our country is!
1. Where does the text come from?| A．A story book. | B．A news report. |
| C．A science fiction. | D．A travel guidebook. |
| A．Applying adaptive climbing skills. | B．Planning the project in early March. |
| C．Inviting many experts to support. | D．Using the most advanced mapping instruments. |
| A．This is the 7th large-scale survey of Qomolangma |
| B．The height of Qomolangma must be shorter than before. |
| C．30 Surveyors were stationed near Qomolangma. |
| D．83 surveyors worked for the remeasurement. |
| A．The ways of remeasuring Qomolangma. |
| B．The results of measuring Qomolangma. |
| C．The technologies applied in remeasuring |
| D．China's remeasurement of Qomolangma. |
