1 . As PhD research goes, Brian Wisenden was enviable, watching baby fish swimming swiftly through the clear waters in the Costa Rican tropical dry forest. By recording their growth and numbers, he hoped to look at their risks of being eaten. Instead, he witnessed something odd. Many groups were increasing in numbers. In these groups, some were smaller than others, suggesting they weren’t siblings (兄弟姐妹). Wisenden had accidentally discovered that the fish, called convict cichlids, adopt each other’s babies. Why would they do that, he wondered?
In the human world, we think of adoption as a selfless act. But in nature, its presence is puzzling. Taking on the burden of bringing up babies with no genetic link would seem to reduce an animal’s chances of survival or at least provide no gain. Yet, adoption is surprisingly common in the world.
Take the eastern grey kangaroo. Between 2008 and 2013, Wisenden followed the fates of 326 baby kangaroos in the National Park in Victoria and recorded 11 cases of pouch swapping. The circumstances behind some of these adoptions aren’t known, but four were straight swaps and another four occurred after a mother had lost her own baby.
How come? Before independence, baby kangaroos go through a period inside and outside their mother’s pouch. Following out-of-pouch forays, mothers normally sniff their young before allowing them back in, but Wisenden’s team suspect that during an emergency they may skip the sniff test, allowing a vulnerable baby to quickly climb in before fleeing from danger. Once inside the wrong pouch, the young may fake the mother’s odor, making them smell confusingly like her own progeny. So, poor baby recognition is the prime cause of “accidental” adoption.
Some of nature’s adoptions are, actually, driven by young looking for better prospects. In burrower bugs, for example, females lay a nest of eggs close to those of unrelated bugs. Mother bugs tend their developing eggs before they hatch, then feed their babies nuts from weedy mint plants. Finding nuts is a competitive business, so not every mother bug gets her fair share. And if the delivery rate isn’t up to scratch, clever young may abandon their mothers to join a better-fed group. That’s similar to behavior in several species of gull whose babies, if poorly fed, may leave home in search of better parents.
The consequences of adoption following mistaken identity can be dire. The true babies of adopting mothers were abandoned. But it can have remarkable benefits, not just for adoptees but also for adoptive parents.
1. It can be inferred from the passage that Wisenden’s findings are .| A．too weird to be witnessed | B．out of his own expectations |
| C．envied by his peer co-researchers | D．a sound proof of his research object |
| A．Baby animals’ looking for better parenting. |
| B．Parents’ failure to recognize their own babies. |
| C．Selfless adoption commonly seen in animal world. |
| D．Parents, inability to provide enough food. |
| A．weak and easily attacked | B．naughty and easily hurt |
| C．independent and well-fed | D．fragile and poorly raised |
| A．The benefits for baby animals. | B．The benefits for adopters. |
| C．The consequences of adoption. | D．The consequences of wrong identity. |
2 . Like all big cities, Paris has a traffic problem: lots of cars. lots of traffic jams and lots of pollution from exhaust fumes(废气). So the city began a scheme(计划)to improve the situation.
Under the Velib scheme ('Velib' comes from velo liberte, or 'bicycle freedom') people can take a bicycle, use it for as long as they want, and then leave it at the same or another bicycle station. The first half-hour-on the bike is free, but if you don't return it after 30 minutes, you have to pay. But it's only € 1 a day or € 29 a year! The bicycles are heavy (25kg), and they are all grey and have baskets. There are about 20,000 of them in the city, and around 1,450 bicycle stations. So there are a lot more Velib stations than the 298 subway stations!
Paris is not the first city to have a scheme like this. But not everybody thinks it's a great idea. One Parisian said. “These bicycles are only for short journeys. If people want to travel across the city, they won't use a bicycle-they'll still use their cars.”
A city spokesman said, “The bicycle scheme won't solve all our traffic problems, of course. But it might help reduce air pollution. Traffic, together with factory fumes, is a big problem. There aren't any simple answers to traffic problems and pollution in cities. But unless we do something now, there will be more traffic jams and temperatures will continue to rise, so the problems in our environment will get worse. The bikes might help people to lead a healthier life, too. “
1. What can we know about the Velib scheme?| A．Its bikes have no baskets. | B．Its bikes are light and colorful. |
| C．It owns more stations than the subway. | D．It aims to make traveling easier. |
| A．€1. | B．€30. | C．€29. | D．No money. |
| A．The cost is rather high. | B．It's not suitable for a long journey. |
| C．It's hard to find a Velib station. | D．The distance between two Velib stations is long. |
| A．Doubtful. | B．worried. | C．Uncaring. | D．Positive. |
Chengdu has dozens of new millionaires, Asia's biggest building, and fancy new hotels. But for tourists like me, pandas are its top
So
On my recent visit, I held a lively three-month-old twin that had been rejected by its mother. The nursery team switches him every few
4 . Used clothes are rather difficult to deal with. They are made from chemicals, cotton, or wool, which consume many resources in the process of manufacturing and, if burned, they pollute the air and increase the carbon pressure upon the environment. Therefore, it is a good thing for used clothes to be recycled in factories instead of being disposed of in garbage cans to be incinerated or transported to landfill sites. In that sense, the companies that put the donation boxes in communities have done something good and beneficial.
However, if they mean to recycle used clothes, they need to tell people that and label their collection boxes as "recycle boxes" instead of misleading people by calling them "donation boxes". People expect their "donated" clothes to go to the poor, not factories.
People need to be more realistic as well. Donating clothes may not bring much help to the poor. Especially, as it takes a lot of human labor to collect the used clothes, sort them, clean and disinfect them and deliver them to less-developed areas. Every step costs money and sometimes the total cost might even be higher than buying new clothes in large quantities. Sometimes the poor might not need used clothing, but they cannot trade the clothes for what they do need.
It might be a sad fact, but the most effective and efficient way of helping poor people is donating money and letting them get what they need themselves. So, when people want to send a helping hand, they need to donate money, instead of simply donating their used, unwanted clothes.
1. What is the first paragraph mainly about?| A．The donation boxes should be put more in communities. |
| B．Unwanted clothes can be recycled in donation boxes. |
| C．Putting donation boxes in communities is right for companies. |
| D．Used clothes should be recycled in factories. |
| A．The poor don’t need clothing donations any longer. |
| B．Recycling these used clothes needs much more money. |
| C．Donation boxes are intended for collecting unwanted clothes. |
| D．The clothes in the boxes are to be recycled at last. |
| A．The poor cannot get help from it. |
| B．The factories cannot benefit from it. |
| C．It’s not convenient for the residents. |
| D．It gets the communities into trouble sometimes. |
| A．Supportive | B．Disapproving |
| C．Indifferent | D．Doubtful |
Imagine
Black holes are one of the most mysterious things in
The photo proves Einstein was right . It makes the general theory of relativity
6 . Young sunflowers turn and swing every day. New findings add to evidence that the plants are animal-like.
Harmer, a professor in the University of California at Davis, Department of Plant Biology, carried out a series of experiments on sunflowers in the field pots outdoors and in indoor growth chambers.
By staking plants so that they could not move, Harmer showed that he could destroy their ability to track the sun. He also noticed that sunflowers prevented from moving were not as tough and leafy as those that were free to move. When plants were moved indoor with a settled overhead light, they continued to swing back and forth for a few days.
The indoor plants did start tracking the "sun" again when the apparent source of lighting was moved across the room. The plants could reliably track the movement and return at night when the artificial day was close to a 24-hour cycle, but not when it was closer to 30 hours.
When sunflowers track the sun, the east sides of their stems grew more rapidly than the west sides. At night, the west sides grew faster as the stem swung the other way. The team identified a number of genes that were expressed at higher levels on the sunward side of the plant during the day, or on the other side at night. A plant growth-regulating hormone, called auxin, appears to be a key driver.
The "dance” to the sun cycle obviously slows when the sunflower matures （成熟） and its flowers open up. At that point, the plants stop moving during the day and settle down facing the sun in the east.
"Bees like warm flowers." Hanner said, adding that the bees are cold-blooded, so landing on a warm flower saves them energy and perhaps feels really good.
“The morning warmth changes the flowers in a way to make them more appealing to insects, perhaps causing them to release more attractive scents earlier in the day." he said "We're currently testing this idea."
1. Why did Harmer do the experiment on sunflowers?| A．To see how sunflowers grow up |
| B．To study why sunflowers track the sun. |
| C．To show what sunflowers' genes are. |
| D．To check if sunflowers swing in cloudy days. |
| A．fixing | B．tracking |
| C．growing | D．searching |
| A．They attract more insects. | B．They save more energy. |
| C．They mature more rapidly | D．They produce more flowers. |
| A．The power of the sunlight. |
| B．The hidden connection between animal and the plants. |
| C．Why do sunflower always track the sun. |
| D．The growth of the sunflower. |
7 . We often ask these questions: Are African wild dogs really dogs? What’s the difference between African wild dogs and the dogs we know as pets? For one thing, African wild dogs, which live in Africa, only have four toes, while domestic(驯养的）dogs and wolves have five. But you won’t want to count for yourself, because they are truly wild animals.
“Wild dogs are not somebody’s domestic dogs that ran away and didn’t come back, although some people used to think that,” explains Dr. MeNutt, who studies these animals at Wild Dog Research Camp in the African country of Botswana. “They are actually Africa’s wolves, and just like wolves, and they do not make good pets. They need to be out in the wild doing what they are supposed to do — find the food they need to survive and feed their babies.” In fact, they travel so far that researchers have to use radio collars (颈圈) to keep track of them. The collars send out radio signals that tell people where the dogs are. No two wild dogs have the same pattern of coats, so it is easy to tell them apart.
African wild dogs are smart and sociable, like pet dogs. Adult wild dogs, male and female, are willing to take good care of young ones.
Millions of domestic dogs live on the planet, but there are probably fewer than 6000 African wild dogs left. Humans hunt them and farmers who don，t want them to go after cows and sheep poison them. Humans are also destroying the wild, natural habitat (栖息地) they need to survive in. Fortunately, today more farmers are finding other ways to protect their cows and sheep from African wild dogs instead of killing the animals.
1. In Dr. MeNutt’s view, African wild dogs ________.| A．can be trained as pet dogs |
| B．are a kind of wolves |
| C．actually are missing domestic dogs |
| D．generally are not used to living in groups |
| A．To tell African wild dogs apart from other dogs. |
| B．To play games with African wild dogs. |
| C．To know where African wild dogs go. |
| D．To prevent African wild dogs from traveling too far. |
| A．There are too many domestic dogs. |
| B．African wild dogs live shorter than domestic dogs. |
| C．African wild dogs are the natural enemies of cows and sheep. |
| D．African wild dogs should be protected instead of being killed. |
| A．How to keep wild dogs. |
| B．How to train domestic dogs. |
| C．An introduction to African wild dogs. |
| D．Differences between domestic dogs and wild dogs. |
8 . The bristlecone pine is the longest-living thing on the earth. These trees, with their strangely-shaped, wind-beaten limbs(枝干), can live up to 5,000 years. But experts worry that a warming climate in some areas may threaten its future.
Researchers say warmer weather is permitting a similar kind of tree, the limber pine, to take over good growing places from the ancient bristlecone. They say the tree is being crowded out of mountainous areas where it grows.
“The bristlecone pine is the oldest individually growing organism,” researchers say. They grow in high mountain forests in eastern California, Nevada and Utah. In those mountains, the trees face high winds and extreme temperatures, which leave them with twisted limbs and shapes. “Even in such tough conditions,” Brian Smithers, a researcher at the University of California, said, “the limber pine is taking all the good spots.”
The limber pine is the bristlecone’s distant relative and competitor. It can also live a long time——up to 2,000 years. And it is usually found at lower altitudes, where temperatures are warmer. However, according to a three-year study which centered on trees that have started growing in the last 50 years in California’s White Mountains, most of the trees growing at higher altitudes were limber pines.
Scientists compared the competing species to two o1d men in a very slow race up a mountainside. This race between such slow-growing trees takes thousands of years. They say climate change is causing the competition.
Smithers said the bristlecone pines are not in danger of disappearing. But he assumes they could be crowded out of some places where they have grown for thousands of years.
The researchers say the findings show how climate change can affect the two kinds of trees. The information, they say, can help scientists understand more complex forests.
1. What’s the function of Paragraph 1?| A．To introduce a topic. | B．To summarize the whole passage. |
| C．To describe the appearance of a tree. | D．To praise the hard work of the experts. |
| A．There will be older trees sent out of those mountains. |
| B．There will be more places covered with bristlecone pines. |
| C．There will be better limber pines replacing the ancient ones. |
| D．There will be fewer bristlecone pines growing in those areas. |
| A．the high winds | B．the difficult conditions |
| C．the changing climate | D．the extreme temperatures |
| A．Positive. | B．Concerned. |
| C．Enthusiastic. | D．Indifferent. |
9 . The loud continuous noise of the cars or the sound of a plane can force its way into the deepest forest, yet it’s not only humans that are bothered by the noise.
Bioacoustician Bernie Krause has been studying the effect of noise pollution on wildlife, and has come across some interesting behaviors, especially among animals that communicate by vocalization（发声）, like humans. Birds use sound to communicate, but in noisy places, these animals have to shout over the natural noise to be heard.
Krause mentions a study of nightingales to clarify what he means. The birds responded to traffic noise by singing louder and louder until they actually went beyond noise pollution standards in the city. To belt out (sing loudly) their songs, they increased their lung pressure fivefold, but scientists state that this is not dangerous for the birds themselves.
Studies show that sudden noise can cause certain birds to leave their nests, exposing the young to their enemies. One study also showed that songbirds that nested close to busy motorways were much less productive than those that nested farther away. Mammals（哺乳动物）too are affected. A recent study showed that nursing caribou responded to plane noise by not producing enough milk to feed their young.
In some cases noise pollution can actually help some animals while harming others. Toads（蟾蜍）and frogs are known to vocalize in synchrony（同步；同步方式）so that no predator (their enemies) can zero in on them. Krause found that when planes flew overhead and disturbed the toad’s song, they lost their synchronicity, and it took them 45 minutes to get it back again. That gave their natural enemies plenty of time to find and catch individual toads by sound.
According to Kruse, “Not only will noise pollution bother wildlife, but it won’t help our lives either.”
1. How do young caribou suffer from aircraft noise?| A．They receive less food. | B．They can’t sleep at night. |
| C．They are often displaced. | D．They can’t hear their mothers. |
| A．They might become defenseless. |
| B．They would stop communicating. |
| C．They would soon regain their rhythm. |
| D．They might ne unable to hunt in groups. |
| A．The effects of noise pollution on wildlife. |
| B．The causes of noise pollution. |
| C．Animals’ reaction to noises. |
| D．The ways animals communicate with each other. |
10 . Washington, D.C. Bicycle Tours
Cherry Blossom Bike Tour in Washington, D.C.
Duration: 3 hours
This small group bike tour is a fantastic way to see a world-famous cherry trees with beautiful flowers of Washington, D.C. Your guide will provide a history lesson about the trees and the famous monuments where they blossom. Reserve your spot before availability — the cherry blossoms—disappear!
Washington Capital Monuments Bicycle Tour
Duration: 3 hours (4 miles)
Join a guided bike tour and view some of the most popular monuments in Washington, D.C. Explore the monuments and memorials on the National Mall as your guide shares unique facts and history at each stop. Guided tour includes bike, helmet, cookies and bottled water.
Capital City Bike Tour In Washington, D.C.
Duration: 3 hours
Morning or Afternoon, this bike tour is the perfect tour for D. C. newcomers and locals looking to experience Washington, D.C. in a healthy way with minimum effort. Knowledgeable guides will entertain you with the most, interesting stories about Presidents, Congress, memorials, and parks. Comfortable bikes and a smooth tour route(路线) make cycling between the sites fun and relaxing.
Washington Capital Sites at Night Bicycle Tour
Duration: 3 hours (7miles)
Join a small group bike tour for an evening of exploration in the heart of Washington, D.C. Get up close to the monuments and memorials as you bike the sites of Capitol Hill and the National Mall. Frequent stops are made for photo taking as your guide offers unique facts and history. Tour includes bike, helmet, and bottled water. All riders are equipped with reflective vests and safety lights.
1. Which tour do you need to book in advance?| A．Cherry Blossom Bike Tour in Washington, D.C. |
| B．Washington Capital Monuments Bicycle Tour. |
| C．Capital City Bike Tour in Washington. |
| D．Washington Capital Sites at Night Bicycle Tour. |
| A．Meet famous people. | B．Go to a national park. |
| C．Visit well-known museums. | D．Enjoy interesting stories. |
| A．City maps. | B．Cameras. |
| C．Meals. | D．Safety lights. |
