【推荐1】Wild elephants wander across the crowded flatland of India; the forest river banks through fields in Brazil; a ribbon (缎带) of green spreads across.Europe where the Iron Curtain used to be. Using such wildlife corridors (走廊) to link up larger but isolated (孤立的) protected areas is the most widely used method for stopping biodiversity decline (生物多样性衰退), with millions of dollars spent creating and protecting them every year. But has enthusiasm for a neat idea got ahead of the science?

As wild habitat is broken into isolated parts by farms, roads and settlements, we need to link them up with corridors of green. Then even if the entire habitat can’t be recreated, old migration (迁徙) patterns can be brought back,escape routes created ahead of climate change and —perhaps most importantly — isolated populations can interbreed (杂交), improving their genetic (基因的) diversity and their ability to-survive.

Recently, Paul Beier, a biologist from Northern Arizona University, and his colleague Andrew Gregory, warned that “in spite of much research, there is little evidence that protection corridors work as expected.” There is, they say, plenty of evidence that wild animals will move through corridors. But supporters of corridors want, and claim, much more than this. They say that animals don’t just go for a walk in their protection woods, but that they move in forever and interbreed with neighbouring populations. In this way corridors supposedly linked isolated and endangered populations into an interbreeding — and much more powerful — whole.

Such claims sometimes hold up. In the United Kingdom, the expansion (扩张) of Kielder Forest in the 1960s provided a link between isolated populations of endangered red squirrels.Genes from isolated populations have now “spread through hundreds of forest parts” across100 kilometers and more. But the Kielder Forest is much wider than an ordinary corridor. Fewstudies have looked for gene exchange in corridors; even fewer have found it, One study researched the genetic diversity of small marsupials (有袋类动物) in a narrow forest corridor crossing 4.5 kilometers of grassland in Queensland, Australia. It found that genetically distinct populations had kept on staying at either end. Mixing was impossible.

Other studies have shown that protection corridors.work. But most have looked at short corridors of 100 meters through largely natural landscape. “That species can travel along short corridors in a natural setting doesn’t mean that they will be successful travelling along much longer corridors which are in a landscape greatly affected by human beings,” says Gregory, “still less that such movements occur frequently enough to allow enough gene exchange to occur so that the connected habitat blocks function as one population.”

Perhaps we shouldn’t make the. perfect the enemy of the good. Is any corridor surely better than none? But consider this. The edges of wild areas are known danger zones for wildlife, where enemies and diseases may invade (侵略). Linking two existing protected areas with a long narrow corridor may uncover it to greater danger along these edges. Unless the benefit exceeds (超过) the threat, then there is serious possibility to do harm.

1. We can infer from Paragraph 1 that people might ________.

A．pay too much attention to biodiversity

B．be.using wrong ways to protect wildlife

C．be too idealistic about protection corridors

D．have given too.much protection to wildlife

2. According to Paragraph 2, wildlife corridors were put forward because of ________.

A．their isolation	B．human activities
C．climate change:	D．alien animals

3. Which of the following would Beier most likely agree with?

A．We should give up wildlife corridors.

B．Animals don’t like to walk in corridors.

C．We need more evidence.to.support how corridors.can work.

D．Corridors can link isolated animals into an interbreeding whole.

4. Kielder Forest is mentioned in Paragraph 4 as an example of the__________.

A．primary corridor	B．unsuccessful corridor
C．ordinary corridor	D．non-typical corridor

5. What’s the author’s attitude to wildlife corridors?

A．Supportive.

B．Doubtful.

C．Disapproving.

D．Unconcerned.

【推荐2】Strange ice rings in Siberia’s Lake Baikal have puzzled scientists for decades, but now the mystery apparently has been solved. The answer: the rings are caused by warm, circular currents of water under the ice, called eddies (漩涡).

The eddies’ strong currents melt the ice at the edge, but weaker ones keep the center frozen. “Results of our field surveys show that there are warm eddies that circulate in a clockwise (顺时针的) direction under the ice cover,” said Alexei Kouraev, a hydrologist at the University of Toulouse, in a NASA statement. “In the eddy center, the ice does not melt — even though the water is warm — because the currents are weak,” he said. “But on the eddy boundary, the currents are stronger, and warmer water leads to rapid melting.”

During field work, Kouraev and his colleagues drilled holes near ice rings and set sensors capable of measuring the temperature and salinity (盐浓度) of the water to a depth of 700 feet. They found that the water in the eddies was 2 to 4 ℉ warmer than the surrounding water.

Most of the rings appear in March or April and have a width of about 3 to 4 miles — too big to recognize from the ground but easily seen from satellites above. Some rings were ephemeral while others lasted for weeks or even months.

Lake Baikal is the world’s largest and deepest freshwater lake, according to Gizmodo. It’s home to many varieties of fish not seen anywhere else in the world, and even a population of freshwater seals.

Researchers are still investigating what causes Baikal’s eddies but think it’s likely because of wind patterns, rivers that flow into the lake and the shape of the lake’s coastline and bottom.

1. Which word can best replace the underlined word “ephemeral” in paragraph 4?

A．Steady.	B．Current.
C．Fundamental.	D．Temporary.

2. Why is the ice in the center of ice rings frozen while that at the edge is melted?

A．Because the center of ice rings is 2 to 4℉ warmer than the edge.

B．Because the currents in the center are less powerful.

C．Because it is too wide to be recognized or melted.

D．Because water in the center circulates in a clockwise direction.

3. Which of the following statements about Lake Baikal’s eddies is TRUE?

A．They are caused by hot and circular currents under the ice.

B．The ice in the center of Lake Baikal’s eddies melts faster than that of the edge.

C．Researchers are uncertain about the exact reason of the eddies’ existence.

D．Lake Beikal’s eddies can only be measured at the depth of 700 feet.

4. What maybe the best title for the passage?

A．What’s causing the giant ice rings in Siberia?

B．The mystery of the eddies' in the Lake Baikal uncovered.

C．The largest and deepest freshwater lake — Lake Baikal.

D．Why does the edge of an ice ring melt faster?

【推荐1】No animals have experienced a greater appearance change in the past few decades than the nonavian(非鸟类的)dinosaurs. We used to think they had nothing but boring gray and brown scales but they are now believed to have had feathers in bright colors and patterns. So what colors were the dinosaurs? And how do we know?

One scientist we have to thank for the answers to both questions is Jakob Vinther. Ever since the first fossilized(成为化石的)dinosaur feathers were reported in 1996, scientists had noticed round tiny structures within them—structures that many had assumed were fossilized bacteria.

But as a doctoral student studying a completely different animal, Vinther realized that these structures might be something more. “I was looking at fossilized ink in a squid-like(像乌贼的)animal. It was remarkably well preserved,”Vinther said. “You can take ink from a squid you bought down at the fish market, put it under a microscope, and see perfect little round balls. And then when you take fossilized ink, it looks exactly the same.” Those balls are melanosomes(黑素体)that color hair, skin, feathers and eyes of animals. These round structures turned out to be the same ones being mistaken for bacteria in dinosaur feathers.

Scientists had largely believed that melanosomes couldn’t survive the fossilization process, but discoveries have shown not only that they survive but that they can tell us the actual colors of extinct animals. That’s because they come not only in “perfect little round balls” but also in many different shapes, each of which produces a different color.

“If you look at a person with black hair or a bird with black feathers, those melanosomes are sausage-shaped,” Vinther said. “If you have orange-brown hair, they’ re shaped like little meatballs. So basically, you just look for sausages and meatballs, and then you can actually put colors on extinct animals.” Once you know the shape of the melanosomes in a fossil, you can learn all sorts of things about the animal.

1. What is the new discovery about nonavian dinosaurs?

A．They had gray and brown scales.	B．They had colorful patterned feathers.
C．They had interesting behavior patterns	D．They had various patterns on their scales.

2. The round tiny structures within fossils once were mistaken for________.

A．Fossilized bacteria

B．Dinosaurs’ scales

C．Fossilized ink

D．Melanosomes

3. How did Jakob Vinther make his discovery?

A．By working with fishermen.

B．By studying previous research.

C．By coloring a squid-like animal.

D．By comparing a squid’s ink and fossilized ink.

4. Why are sausages and meatballs mentioned in the last paragraph?

A．To explain the shape of fossilized bacteria.

B．To show how melanosomes form in animals.

C．To explain what decides the colors of animals.

D．To show how melanosomes survive the fossilization process.

【推荐2】Thirst is one of the fundamental urges a living thing can have. After all, water is the solvent that we rely on to transport essential molecules (分子) around our bodies to keep us alive. So it is perhaps a bit suspicious that water doesn’t seem to have any flavor. Shouldn’t we have evolved a taste for this essential substance?

Well, perhaps we have. Several new studies seem to indicate not only that water does, in fact, have a taste, but that we might have taste buds (味蕾) that respond directly to it.

We now know that there are at least five basic tastes: salty, sour, sweet, bitter and umami. If there is a sixth taste for water, then we should be able to see evidence for it somewhere in the mouth or tongue. Yuki Oka and his colleagues have sought to solve the issue once and for all. They have thought up an experiment that seeks to identify any water sensing taste receptor cells (TRCs) on the tongues of lab mice.

The team first used a technique known as genetic knockout to silence different types of TRCs, in order to remove the possibility that those cells might accidentally discover some other taste within the water besides the water itself. They then flushed the rodents’ mouths with water to see if any cells were still responding. It turned out that the acid-sensing sour TRCs were still firing vigorously indicating these cells might have a double purpose, capable of distinguishing water or acidic fluids.

So if you are on the side of the debate that argues that water is flavorless, you might still be correct. But water isn’t senseless. At least it doesn’t appear that way according to this research. The study also opens up the possibility that our tongues and taste buds might be doing more than merely providing us with a sense of taste. If this study doesn’t prove that water is the sixth flavor, it might nonetheless be the first evidence of a whole other sense entirely: a water sense.

1. Why is the question asked in the first paragraph?

A．To introduce the main topic.

B．To show ordinary people’s puzzlement.

C．To express the writer’s curiosity.

D．To explain the reason for suspicion.

2. What does the underlined word “rodents” refer to?

A．Researchers.	B．Yuki oka’s colleagues.
C．Thirsty people	D．Mice.

3. It can be inferred that genetic knockout is a technique ________.

A．to create some cells	B．to remove some cells
C．to identify some certain cells	D．to disable some cells

4. What can be leaned from the experiment?

A．Water is flavors without doubt.

B．Water is the sixth flavor.

C．Water can be sensed.

D．Water can attack TRCs.

【推荐3】Will your job be done by a robot in the future? Bank of England economists predict that almost half of all UK jobs are under threat of robots. Those most at risk are physical labor, such as factory workers. But could even teachers soon have to compete against powerful electronic educators?

At fist sight, teaching might seem impossible to be replaced by robots. Teachers use a lot of soft skills. Those skills are hard to be copied by machines. They judge students’ needs and adapt materials to make them more effective. And they provide special care: looking out for students who drop behind or make trouble in class.

Anyhow, some believe the future of education will be technological. In an interview, futurist Thomas predicts that “by 2030 the largest company on the Internet is going to be an education-based company that we haven’t heard of yet.”

He thinks that online robot teachers will make education so efficient that students will be able to finish an entire undergraduate degree in six months of learning. A robot teacher learns what your “characters”, “interests” and “reference points” are, “and it knows how to teach you in a faster and faster way over time,” according to Thomas.

Over the last decade, there has been a huge increase in online learning. Many companies produce courses that allow millions to learn at home for free, at their own pace. But there are limitations. Without the face-to-face encouragement of a classroom environment, most of the students fail to complete online courses. How to encourage students to learn is one more skill that online teachers will need to master.

Indeed, Thomas admits there is some way to go and he thinks that we should hug the change, even though people will lose their jobs.

1. Which job is most probably to be replaced by robots?

A．Dustmen.

B．Doctors.

C．Directors.

D．Judges.

2. What’s the disadvantage of online learning?

A．Studying alone.	B．Staying at home.
C．Learning at your own speed	D．Lacking direct inspiration.

3. What’s the best title for the passage?

A．What Will the Future Job Be Like?	B．Education of the Future
C．What Can We Do about Online Learning?	D．Robot Teacher of the Future