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Afterwards there was just a feeling of let-down. excitement anger calm disappointment
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They are trying to identify what is wrong with the present system. prove consider imagine discover
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His stomach felt hollow with fear. empty sincere respectful terrible
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It was a magic night until the spell was broken. time charm space opportunity
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The committee was asked to render a report on the housing situation. copy furnish publish summarize
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His knowledge of French is fair. very useful quite good very limited rather special
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London quickly became a flourishing port. successful major large commercial
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Several windows had been smashed. broken cleaned replaced fixed
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The worst agonies of the war were now beginning, pains parts aspects results
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The curriculum was too narrow and too rigid. hidden traditional inflexible official
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The majority of people around here are decent. real honest normal wealthy
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His professional career spanned 16 years. started changed moved lasted
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He led a very moral life. human intelligent natural honourable
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The group does not advocate the use of violence. limit support regulate oppose
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She felt that she had done her good deed for the day. act homework justice model
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So Many “Earths“
The Milky Way(银河)contains billions of Earth-sized planets that could support life. That’ s the finding of a new study. It draws on data that came from NASA’ s top planet-hunting telescope.
A mechanical failure recently put that Kepler space telescope out of service. Kepler had played a big role in creating a census of planets orbiting some 170, 000 stars. Its data have been helping astronomers predict how common planets are in our galaxy. The telescope focused on hunting planets that might have conditions similar to those on Earth.
The authors of a study, published in The Proceedings of the National Academy of Sciences, conclude that between 14 and 30 out of every 100 stars, with a mass and temperature similar to the Sun, may host a planet that could support life as we know it. Such a planet would have a diameter at least as large as Earth’ s, but no more than twice that big. The planet also would have to orbit in a star’ s habitable zone. That’ s where the surface temperature would allow any water to exist as a liquid.
The new estimate of how many planets might fit these conditions comes from studying more than 42, 000 stars and identifying suitable worlds orbiting them. The scientists used those numbers to extrapolate(推算)to the rest of the stars that the telescope could not see.
The estimate is rough, the authors admit. If applied to the solar system, it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars. Neither planet is Earthlike(although either might have been in the distant past). Using tighter limits, the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world. These are ones that would take 200 to 400 days to complete a yearly orbit.
Four out of every 100 sunlike stars doesn’ t sound like a big number. It would mean, however, that the Milky Way could host more than a billion Earth-sized planets with a chance for life.
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A. the extra heat
B. rapid exaggeration of impacts
C. the exposed ground
D. recorded history
E. a very long time
F. previously published studies
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Climate Change; The Long Reach
1 Earth is warming. Sea levels are rising. There’ s more carbon in the air, and Arctic ice is melting faster than at any time in recorded history. Scientists who study the environment to better gauge(评估)Earth’ s future climate now argue that these changes may not reverse for a very long time.
2 People burn fossil fuels like coal and oil for energy. That burning releases carbon dioxide, a colorless gas. In the air, this gas traps heat at Earth’s surface. And the more carbon dioxide released, the more the planet warms. If current consumption of fossil fuels doesn’ t slow, the long-term climate impacts could last thousands of years—and be more severe than scientists had been expecting. Climatologist Richard Zeebe of the University of Hawaii at Manoa offers this conclusion in a new paper.
3 Most climate-change studies look at what’ s going to happen in the next century or so. During that time, changes in the planet’ s environment could nudge(推动)global warming even higher. For example, snow and ice reflect sunlight back into space. But as these melt, sunlight can now reach—and warm—the exposed ground. This extra heat raises the air temperature even more, causing even more snow to melt. This type of rapid exaggeration of impacts is called a “fast feedback“.
4 Zeebe says it’ s important to look at fast feedbacks. However, he adds, they’ re limited. From a climate change perspective, “ This century is the most important time for the next few generations, “ he told Science News. “But the world is not ending in 2100. “ For this new study, Zeebe now focuses on “slow feedbacks“. While fast feedback events unfold over decades or centuries, slow feedbacks can take thousands of years. Melting of continental ice sheets and the migration of plant life—as they relocate to more comfortable areas—are two examples of slow feedbacks.
5 Zeebe gathered information from previously published studies investigating how such processes played out over thousands of years during past dramatic changes in climate. Then he came up with a forecast for the future that accounts for both slow and fast feedback processes. Climate forecasts that use only fast feedbacks predict a 4.5 degree Celsius(8.1 degree Fahrenheit)change by the year 3000. But slow feedbacks added another 1.5° C—for a 6°C total increase, Zeebe reports. He also found that slow feedback events will cause global warming to persist for thousands of years after people run out of fossil fuels to burn.
A. Fast Feedbacks
B. A Prediction of Future Climate Change
C. Rising of Sea Levels
D. Slow Feedbacks
E. Impact of Burning Fossil Fuels
F. Unpredictability of Feedback Processes
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Eye-tracker Lets You Drag and Drop Files with a Glance
Bored of using a mouse? Soon you’ 11 be able to change stuff on your computer screen—and then move it directly onto your smartphone or tablet(平板电脑)—with nothing more than a glance.
A system called EyeDrop uses a head-mounted eye tracker that simultaneously records your field of view so it knows where you are looking on the screen. Gazing at an object—a photo, say—and then pressing a key, selects that object. It can then be moved from the screen to a tablet or smartphone just by glancing at the second device, as long as the two are connected wirelessly.
“The beauty of using gaze to support this is that our eyes naturally focus on content that we want to acquire, “ says Jayson Turner, who developed the system with colleagues at Lancaster University, UK.
Turner believes EyeDrop would be useful to transfer an interactive map or contact information from a public display to your smartphone or tablet for sharing photos.
A button needs to be used to select the object you are looking at otherwise you end up with the “ Midas touch“(点石成金)effect, whereby everything you look at gets selected by your gaze, says Turner. “Imagine if your mouse clicked on everything it pointed at, “ he says.
Christian Holz, a researcher in human-computer interaction at Yahoo Labs in Sunnyvale, California, says the system is a nice take on getting round this fundamental problem of using gaze-tracking to interact. “EyeDrop solves this in a slick(灵巧的)way by combining it with input on the touch devices we carry with us most of the time anyway and using touch input as a clutching mechanism, “ he says, “ This now allows users to seamlessly(无缝地)interact across devices far and close in a very natural manner. “
While current eye-trackers are rather bulky, mainstream consumer devices are not too far away. Swedish firm Tobii is developing gaze-tracking technology that can be installed in laptops and tablets and is expected to be available to buy next year. And the Google Glass headset is expected to include eye-tracking in the future.
Turner says he has also looked at how content can be cut and pasted or drag-and-dropped using a mix of gaze and taps on a touchscreen. The system was presented at the Conference on Mobile and Ubiquitous Multimedia in Sweden, last week.
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The Mir Space Station
The Russian Mir Space Station, which came down in 2001 at last after 15 years of pioneering the concept of long-term human space flight, is remembered for its accomplishments in the human space flight history. It can be credited with many firsts in space.
During Mir’s lifetime, Russia spent about US $4.2 billion to build and maintain the station.
The Soviet Union launched Mir, which was designed to last from three to five years, on February 20, 1986, and housed 104 astronauts over 12 years and seven months, most of whom were not Russian. In fact, it became the first international space station by playing host to 162 people from 11 countries. From 1995 through 1998, seven astronauts from the United States took turns living on Mir for up to six months each. They were among the 37 Americans who visited the station during nine stopovers by space shuttles.
The more than 400 million the United States provided Russian for the visits not only kept Mir operating, but also gave the Americans and their partners in the international station project valuable experience in long-term flight and multinational operations.
A debate continues over Mir’ s contributions to science. During its existence, Mir was the laboratory for 23, 000 experiments and carried scientific equipment, estimated to be worth $ 80 million, from many nations. Experiments on Mir are credited with a range of findings, from the first solid measurement of the ration of heavy helium(ft, )atoms in space to how to grow wheat in space. But for those favouring human space exploration, Mir showed that people could live and work in space long enough for a trip to Mars. The longest single stay in space is the 437. 7 days that Russian astronaut Valery Polyakov spent on Mir from 1994 to 1995. And Sergie Avdeyev accumulated 747. 6 days in space in three trips to the space station. The longest American stay was that of Shannon Lucid, who spent 188 days aboard Mir in 1996.
Despite the many firsts Mir accomplished, 1997 was a bad year out of 15 for Mir. In 1997, an oxygen generator caught fire. Later, the main computer system broke down, causing the station to drift several times and there were power failures. Most of these problems were repaired, with American help and suppliers, but Mir’ s reputation as a space station was ruined.
Mir’ s setbacks are nothing, though, when we compare them with its accomplishments. Mir was a tremendous success, which will be remembered as a milestone in space exploration and the space station that showed long-term human habitation in space was possible. But it’ s time to move on to the next generation. The International Space Station being built will be better, but it owes a great debt to Mir.
