|1. D||22. flies and beetles|
|2. B||23. furry coats|
|3. C||24. longer distances|
|4. B||25. worker bees|
|5. D||26. C OR E IN EITHER ORDER|
|6. YES||27. C OR E IN EITHER ORDER|
|7. NO||28. YES|
|8. NO||29. NO|
|9. NOT GIVEN||30. NOT GIVEN|
|10. NOT GIVEN||31. NO|
|11. B||32. NOT GIVEN|
|12. D||33. C|
|13. G||34. A|
|14. E||35. D|
|15. v||36. B|
|16. viii||37. B|
|17. vi||38. H|
|18. x||39. A|
|19. i||40. D|
|20. iii||41. G|
|Level||Band||Listening Score||Reading Score|
Legend: Academic word (?) New word
Khan Academy is changing the rules of education
I peer over his shoulder at his laptop screen to see the math problem the fifth-grader is pondering. It's a trigonometry problem. Carpenter, a serious-feced ten-year-old, pauses for a second, fidgets, then clicks on ”0 degrees." The computer tells him that he's correct. " It took a while for me to work it out ," he admits sheepishly. The software then generates another problem, followed by another, until eventually he's done ten in a row.
Last November, his teacher, Kami Thordarson, began using Khan Academy in her class. It is an educational website on which students can watch some 2,400 videos. The videos are anything but sophisticated. At seven to 14 minutes long, they consist of a voiceover by the site's founder, Salman Khan, chattily describing a mathematical concept or explaining how to solve a problem, while his hand-scribbled formulas and diagrams appear on-screen . As a student, you can review a video as many times as you want, scrolling back several times over puzzling parts and fast-forwarding through the boring bits you already know. Once you've mastered a video, you can move on to the next one.
Initially, Thordarson thought Khan Academy would merely be a helpful supplement to her normal instruction. But it quickly became far more than that. She is now on her way to "flipping" the way her class works. This involves replacing some of her lectures with Khan's videos , which students can watch at home. Then in class, they focus on working on the problem areas together. The idea is to invert the normal rhythms of school, so that lectures are viewed in the children's own time and homework is done at school. It sounds weird, Thordarson admits, but this reversal makes sense when you think about it. It is when they are doing homework that students are really grappling with a subject and are most likely to want someone to talk to. And Khan Academy provides teachers with a dashboard application that lets them see the instant a student gets stuck.
For years, teachers like Thordarson have complained about the frustrations of teaching to the "middle" of the class. They stand at the whiteboard trying to get 25 or more students to learn at the same pace. Advanced students get bored and tune out, lagging ones get lost and tune out, and pretty soon half the class is not paying attention. Since the rise of personal computers in the 1980s, educators have hoped that technology could save the day by offering lessons tailored to each child. Schools have spent millions of dollars on sophisticated classroom technology, but the effort has been in vain . The one-to-one instruction it requires is, after all, prohibitively expensive. What country can afford such a luxury?
Khan never intended to overhaul the school curricula and he doesn't have a consistent, comprehensive plan for doing so . Nevertheless, some of his fans believe that he has stumbled onto the solution to education's middle-of-the-class mediocrity . Most notable among them is Bill Gates, whose foundation has invested $1.5 million in Khan's site. Students have pointed out that Khan is particularly good at explaining all the hidden, small steps in math problems— steps that teachers often gloss over . He has an uncanny ability to inhabit the mind of someone who doesn't already understand something.
However, not all educators are enamoured with Khan and his site. Gary Stager, a longtime educational consultant and advocate of laptops in classrooms,, thinks Khan Academy is not innovative at all. The videos and software modules, he contends, are just a high-tech version of the outdated teaching techniques—lecturing and drilling. Schools have become "joyless test-prep factories," he says, and Khan Academy caters to this dismal trend .
As Sylvia Martinez, president of an organization focusing on technology in the classroom, puts it, "The things they're doing are really just rote." Flipping the classroom isn't an entirely new idea, Martinez says, and she doubts that it would work for the majority of pupils : "I'm sorry, but if they can't understand the lecture in a classroom, they're not going to grasp it better when it's done through a video at home."
Another limitation of Khan's site is that the drilling software can only handle questions where the answers are unambiguously right or wrong, like math or chemistry; Khan has relatively few videos on messier, grey-area subjects like history. Khan and Gates admit there is no easy way to automate the teaching of writing—even though it is just as critical as math.
Even if Khan is truly liberating students to advance at their own pace, it is not clear that schools will be able to cope. The very concept of grade levels implies groups of students moving along together at an even pace . So what happens when, using Khan Academy, you wind up with a ten-year- old who has already mastered high-school physics? Khan's programmer, Ben Kamens, has heard from teachers who have seen Khan Academy presentations and loved the idea but wondered whether they could modify it "to stop students from becoming this advanced ."
Khan's success has injected him into the heated wars over school reform. Reformers today, by and large, believe student success should be carefully tested, with teachers and principals receiving better pay if their students advance more quickly. In essence, Khan doesn't want to change the way institutions teach; he wants to change how people learn, whether they're in a private school or a public school—or for that matter, whether they're a student or an adult trying to self-educate in Ohio, Brazil, Russia, or India. One member of Khan's staff is spearheading a drive to translate the videos into ten major languages. It's classic start-up logic: do something novel, do it with speed, and the people who love it will find you.
Adapted from Wired Magazine
They are the Earth’s pollinators and they come in more than 200,000 shapes and sizes.
A Row upon row, tomato plants stand in formation inside a greenhouse. To reproduce, most flowering plants depend on a third party to transfer pollen between their male and female parts. Some require extra encouragement to give up that golden dust. The tomato flower, for example, needs a violent shake, a vibration roughly equivalent to 30 times the pull of Earth’s gravity, explains Arizona entomologist Stephen Buchmann. Growers have tried numerous ways to rattle pollen from tomato blossoms. They have used shaking tables, air blowers and blasts of sound . But natural means seem to work better.
B It is no surprise that nature’s design works best. What’s astonishing is the array of workers that do it: more than 200,000 individual animal species, by varying strategies, help the world's 240,000 species of flowering plants make more flowers . Flies and beetles are the original pollinators, going back to when flowering plants first appeared 130 million years ago. As for bees, scientists have identified some 20,000 distinct species so far. Hummingbirds, butterflies, moths, wasps and ants are also up to the job. Even non-flying mammals do their part: sugar-loving opossums, some rainforest monkeys, and lemurs in Madagascar, all with nimble hands that tear open flower stalks and furry coats to which pollen sticks. Most surprising, some lizards, such as geckos, lap up nectar and pollen and then transport the stuff on their faces and feet as they forage onward.
C All that messy diversity, unfortunately, is not well suited to the monocrops and mega-yields of modern commercial farmers Before farms got so big, says conservation biologist Claire Kremen of the University of California, Berkeley, ‘we didn’t have to manage pollinators. They were all around because of the diverse landscapes. Now you need to bring in an army to get pollination done. The European honeybee was first imported to the US some 400 years ago.
Now at least a hundred commercial crops rely almost entirely on managed honeybees, which beekeepers raise and rent out to tend to big farms. And although other species of bees are five to ten times more efficient, on a per-bee basis, at pollinating certain fruits, honeybees have bigger colonies, cover longer distances , and tolerate management and movement better than most insects. They're not picky - they’ll spend their time on almost any crop. It’s tricky to calculate what their work is truly worth; some economists put it at more than $200 billion globally a year.
D Industrial-scale farming, however, may be wearing down the system. Honeybees have suffered diseases and parasite infestations for as long as they've been managed, but in 2006 came an extreme blow .
Around the world, bees began to disappear over the winter in massive numbers. Beekeepers would lift the lid of a hive and be amazed to find only the queen and a few stragglers, the worker bees gone.
In the US, a third to half of all hives crashed; some beekeepers reported colony losses near 90 percent. The mysterious culprit was named colony collapse disorder (CCD) and it remains an annual menace - and an enigma.
E When it first hit, many people, from agronomists to the public, assumed that our slathering of chemicals on agricultural fields was to blame for the mystery . Indeed, says Jeff Pettis of the USDA Bee Research Laboratory, ‘we do find more disease in bees that have been exposed to pesticides, even at low levels.’ But it is likely that CCD involves multiple stressors. Poor nutrition and chemical exposure, for instance, might wear down a bee's immunities before a virus finishes the insect off. It’s hard to tease apart factors and outcomes, Pettis says. New studies reveal that fungicides - not previously thought toxic to bees - can interfere with microbes that break down pollen in the insects’ guts, affecting nutrient absorption and thus long-term health and longevity. Some findings pointed to viral and fungal pathogens working together. ‘I only wish we had a single agent causing all the declines,’ Pettis says, ’that would make our work much easier!
F However, habitat loss and alteration, he says, are even more of a menace to pollinators than pathogens . Claire Kremen encourages farmers to cultivate the flora surrounding farmland to help solve habitat problems . ‘You can't move the farm,’ she says, ‘but you can diversify what grows in its vicinity: along roads, even in tractor yards.’ Planting hedgerows and patches of native flowers that bloom at different times and seeding fields with multiple plant species rather than monocrops 'not only is better for native pollinators, but it’s just better agriculture,’ she says. Pesticide-free wildflower havens, adds Buchmann, would also bolster populations of useful insects. Fortunately, too, ‘there are far more generalist plants than specialist plants, so there's a lot of redundancy in pollination,’ Buchmann says. ‘Even if one pollinator drops out, there are often pretty good surrogates left to do the job. The key to keeping our gardens growing strong, he says, is letting that diversity thrive.
G Take away that variety, and we'll lose more than honey . ‘We wouldn't starve,’ says Kremen. ‘But what we eat, and even what we wear pollinators, after all, give us some of our cotton and flax - would be limited to crops whose pollen travels by other means. ‘In a sense,’ she says, ‘our lives would be dictated by the wind. It’s vital that we give pollinators more of what they need and less of what they don't, and ease the burden on managed bees by letting native animals do their part , say scientists.
Adapted from National Geograptiic Magazine.
The community that focuses its efforts on the exploration of space has largely been different from the community focused on the study and protection of the Earth's environment, despite the fact that both fields of interest involve what might be referred to as "scientific exploration' . The reason for this dichotomous existence is chiefly historical . The exploration of the Earth has been occurring over many centuries, and the institutions created to do it are often very different from those founded in the second part of the 20th century to explore space. This separation is also caused by the fact that space exploration has attracted experts from mainly non-biological disciplines - primarily engineers and physicists - but the study of Earth and its environment is a domain heavily populated by biologists.
The separation between the two communities is often reflected in attitudes. In the environmental community, it is not uncommon for space exploration to be regarded as a waste of money, distracting governments from solving major environmental problems here at home. In the space exploration community, it is not uncommon for environmentalists to be regarded as introspective people who divert attention from the more expansive visions of the exploration of space - the ‘new frontier’. These perceptions can also be negative in consequence because the full potential of both communities can be realised better when they work together to solve problems. For example, those involved in space exploration can provide the satellites to monitor the Earth’s fragile environments, and environmentalists can provide information on the survival of life in extreme environments .
In the sense that Earth and space exploration both stem from the same human drive to understand our environment and our place within it, there is no reason for the split to exist. A more accurate view of Earth and space exploration is to see them as a continuum of exploration with many interconnected and mutually beneficial links. The Earth and Space Foundation, a registered charity, was established for the purposes of fostering such links through field research and by direct practical action.
Projects that have been supported by the Foundation include environmental projects using technologies resulting from space exploration: satellite communications, GPS, remote sensing, advanced materials and power sources. For example, in places where people are faced with destruction of the forests on which their livelihood depends, rather than rejecting economic progress and trying to save the forests on their intrinsic merit, another approach is to enhance the value of the forests - although these schemes must be carefully assessed to be successful . In the past, the Foundation provided a grant to a group of expeditions that used remote sensing to plan eco-tourism routes in the forests of Guatemala, thus providing capital to the local communities through the tourist trade. This novel approach is now making the protection of the forests a sensible economic decision.
The Foundation funds expeditions making astronomical observations from remote, difficult-to-access Earth locations, archaeological field projects studying the development of early civilisations that made significant contributions to astronomy and space sciences, and field expeditions studying the way in which views of the astronomical environment shaped the nature of past civilisations. A part of Syria - ‘the Fertile Crescent’ - was the birthplace of astronomy, accountancy, animal domestication and many other fundamental developments of human civilisation. The Foundation helped fund a large archaeology project by the Society for Syrian Archaeology at the University of California, Los Angeles, in collaboration with the Syrian government that used GPS and satellite imagery to locate mounds, or ’tels’, containing artefacts and remnants of early civilisations . These collections are being used to build a better picture of the nature of the civilisations that gave birth to astronomy.
Field research also applies the Earth’s environmental and biological resources to the human exploration and settlement of space. This may include the use of remote environments on Earth, as well as physiological and psychological studies in harsh environments . In one research project, the Foundation provided a grant to an international caving expedition to study the psychology of explorers subjected to long-term isolation in caves in Mexico . The psychometric tests on the cavers were used to enhance US astronaut selection criteria by the NASA Johnson Space Center.
Space-like environments on Earth help us understand how to operate in the space environment or help us characterise extraterrestrial environments for future scientific research . In the Arctic, a 24-kilometrewide impact crater formed by an asteroid or comet 23 million years ago has become home tc a Mars- analogue programme. The Foundation helped fund the NASA Haughton-Mars Project to use this crater to test communications and exploration technologies in preparation for the human exploration of Mars. The crater, which sits in high Arctic permafrost, provides an excellent replica of the physical processes occurring on Mars, a permafrosted, impact-altered planet . Geologists and biologists can work at the site to help understand how impact craters shape the geological characteristics and possibly biological potential of Mars .
In addition to its fieldwork and scientific activities. the Foundation has award programmes. These include a series of awards for the future human exploration of Mars, a location with a diverse set of exploration challenges. The awards will honour a number of ‘firsts’ on Mars that include landing on the surface, undertaking an overland expedition to the Martian South Pole, undertaking an overland expedition to the Martian North Pole, climbing Olympus Mons, the highest mountain in the solar system, and descending to the bottom of Valles Marineris, the deepest canyon on Mars. The Foundation will offer awards for expeditions further out in the solar system once these Mars awards have been claimed. Together, they demonstrate that the programme really has no boundary in what it could eventually support, and they provide longevity for the objectives of the Foundation .