Heading to the beach is a popular option for lots of people on a hot summer's day. It's there that you'll find plenty of sand. But could sand be more important than we've ever realized? A team of scientists have found a very different use for the tiny grains that we like to play with on the beach.
They've come up with a type of measurement which will allow them to figure out what's known as the "age distribution fingerprint" of the mineral zircon, which is found within sand. The researchers believe this could provide them with new information on how the Earth's surface has changed over the last few thousand million years.
Some minerals, like zircon, have stood the test of time, and are thought to carry clues of Earth's history. By studying the zircon found in grains of sand from rivers and rocks, the scientists are able to work out previously hidden details about the Earth's past. "Strong and lasting minerals like zircon paint a vivid picture of the planet's history, including changing environments, the evolution of continents, and the accumulation of mineral resources at ancient p late boundaries," said Dr Milo Barham, who worked on the research. “The world's beaches faithfully record a detailed history of our planet's geological past, with billions of years of Earth's history marked in the geology(地质状况)of each grain of sand and our technique helps unlock the information.”
The scientists tried out their new technique by taking a look at sediment(沉淀物)in South America, East Antarctica, and Western Australia and they found some interesting differences. "The sediment on the west and east coasts of South America is completely different because there are many young grains on the west side that were created beneath the continent. However, on the east coast, all is relatively calm geologically and there is a mix of old and young grains," said professor Chris Kirkland, who also worked on this research.
1. What do the underlined words "a very different use" in paragraph 1 refer to?| A．Sand can provide a geological history of the Earth's surface. |
| B．Sand can reconstruct the conditions of mineral formation. |
| C．Sand can help discover the age distribution fingerprint. |
| D．Sand can be used to kill time on a hot summer's day. |
| A．Its cost is extremely low. | B．Its zircon is hard and long-lasting. |
| C．It exists all over the world. | D．It's experienced many changes. |
| A．The west coast is relatively calm geologically. |
| B．The east coast is more active than the west one. |
| C．Its beaches have revealed the Earth's mysteries. |
| D．The grains on the west and east coast have different ages. |
| A．History of grains of sand |
| B．Interesting differences of sediment |
| C．A new technique will trace the human past |
| D．Sand can unlock what happened to Earth |
相似题推荐
【推荐1】Starman, the dummy(仿真人) riding a cherry-red Tesla Roadster(特斯拉敞篷车) through space, has made his closest approach ever to Mars. The electric roadster and its passenger were attached to the top of a Falcon Heavy rocket during the SpaceX rocket’s first test launch on 6 February 2018.
Two years later, the Falcon Heavy rocket and the vehicle at its tip are making their second trip around the Sun. Mr. McDowell, a Harvard astrophysicist, found that Starman passed 7.4 million kilometers from Mars at 06:25 GMT 7 October, 2020.
The closest recent approach between the Earth and Mars was 56 million kilometers in 2003, though the planets are often hundreds of millions of miles apart depending on where they are in their orbits. No one can see the Falcon Heavy rocket at its current distance, but orbits over periods of a few years are fairly straightforward to predict, and Mr. McDowell used data about how the rocket was moving when it left the Earth’s gravity behind to locate its recent movements exactly.
Last time Starman circled the Sun, McDowell said, it crossed Mars’ orbit while the Red Planet was quite far away. But this time the crossing lined up with a fairly close approach, though still not close enough to feel a strong tug from Mars.
At this point in time, if you were able to go look at the Roadster, it would probably look pretty different. The strong solar radiation environment between the planets would probably have destroyed all the exposed organic materials.
Without the Earth’s atmospheric and magnetic(磁场的) protection, even the plastics and carbon-fibre materials would start to break up. Over the course of decades or centuries, the car will end up with its aluminium(铝) frame and hard glass parts----that’s assuming that none of them get destroyed in impacts with passing space rocks.
1. What can we infer from the first two paragraphs?| A．Starman is now circling around the Earth in its orbit. |
| B．Starman has set out on its second trip around the Sun. |
| C．Starman has traveled 7.4 million kilometers after launch. |
| D．Starman still has a long way to go before getting to Mars. |
| A．By keeping Starman under visual observation. |
| B．By predicting its future orbit around the earth. |
| C．By seeking professional help from SpaceX. |
| D．By analyzing data about the rocket’s movement. |
| A．pull | B．drive | C．resistance | D．pressure |
| A．It is circling around Mars and will finally crash onto it. |
| B．It will finish its mission and return to SpaceX on earth. |
| C．Starman is likely reduced to at most its frame and glass. |
| D．SpaceX will try to recover it during its next space mission. |
【推荐2】In an empty parking lot, a car “thinks” it is on a real road. Researchers at the Ohio State University have developed new software to aid in the development, evaluation and demonstration of safer driverless vehicles. Called the Vehicle-in-Virtual-Environment (VVE) method, it allows the testing of driverless cars in a perfectly safe environment, said Bilin Aksun-Guvene, co-author of the study and a professor of Ohio State.
Although autonomous driving technologies have become a much more common sight on the road in the last few years, due to the increasing number of accidents these systems have caused. the way these technologies are tested deserves closer observation.
Current approaches for demonstrating autonomous vehicle functions involve testing software and technology first in simulations (模拟) and then on public roads. Yet this method essentially turns other road users into involuntary participants in these driving experiments. Such risks can make the entire development process costly, inefficient, and potentially unsafe for both drivers and pedestrians (行人) alike.
To overcome the limitations of these faulty assessments, researchers in this study equipped a real vehicle with simulated data to connect its controls to a highly realistic 3D environment. much like giving the machine a VR headset or virtual reality glasses. After feeding the data to the driving system’s computers and syncing (同步) the car’s real motions with the simulations’, researchers were able to show that it behaves as if the virtual environment were its true surroundings in real time.
But what makes their software especially powerful, said Aksun-Guvenc, is the strength of how flexible their virtual environment can be. “When actual senses are replaced by virtual senses, the model can be easily changed to fit any kind of scenario,” said Guvenc.
“We could see this technology becoming an important product in the industry in the next 5 or 10 years. That’s why we’re focusing on building more applications for it.” Guvene added.
1. What can we say about autonomous driving?| A．It is free of dangers. | B．It definitely has a long way to go. |
| C．Its safety testing matters. | D．Its technology is mature. |
| A．Safe and real. | B．Easy and cheap. |
| C．Costly and inefficient. | D．Tough and complicated. |
| A．Strategy. | B．Experiment. | C．Revision. | D．Situation. |
| A．Overcoming the Limitations of Autonomous Driving |
| B．Testing Real Driverless Cars in a Virtual Environment |
| C．Making Autonomous Driving More Common on the Road |
| D．Focusing on Building More Applications for Driverless Cars |
【推荐3】Space exploration has always been the province of dreamers: The human imagination soars where human ingenuity (创造力) struggles to follow. A Voyage to the Moon, often cited as the first science fiction story, was written by Cyrano de Bergerac in 1649. Cyrano was dead and buried for a good three centuries before the first manned rockets started to fly.
In 1961, when President Kennedy declared that America would send a man to the moon by the decade’s end, those words, too, had a dreamlike quality. They reflected optimism and ambition in much the same way as the most famous dream speech of all, delivered by Martin Luther King Jr. two years later. By the end of the decade, both visions had yielded concrete results and transformed American society. And yet in many ways the two dreams ended up at odds with each other. The fight for racial and economic equality is intensely pragmatic (讲求实用的) and immediate in its impact. The urge to explore space is just the opposite. It is literally unrealistic in its aims.
When the dust settled, the space dreamers lost out. There was no grand follow-up to the Apollo missions. The technologically compromised space shuttle program has just come to an end, with no successor. The continuous argument is that funds are tight, that we have more pressing problems here on Earth. Amid the current concerns about the federal deficit (联邦赤字), reaching toward the stars seems an unnecessary luxury--as if saving one-thousandth of a single year’s budget would solve our problems.
But human ingenuity struggles on. NASA is developing a series of robotic probes that will get the most bang for a buck. They will serve as modern Magellan, mapping out the solar system for whatever explorers follow, whether man or machine. On the other hand, companies like Virgin Galactic are plotting a bottom-up attack on the space dream by making it a reality to the public. Private spaceflight could lie within reach of rich civilians in a few years. Another decade or two and it could go main stream.
The space dreamers end up benefiting all of us--not just because of the way they expand human knowledge, or because of the technologies they produce, but because the two types of dreams feed off each other. Both Martin Luther King and John Kennedy appealed to the idea that humans can transcend what were once considered inherent limitations. Today we face challenges in energy, the environment and healthcare. Tomorrow we will transcend these as well, and the dreamers will deserve a lot of the credit. The more evidence we collect that our species is capable of greatness, the more we will actually achieve it.
1. The author mentions Cyrano de Bergerac in order to show that ________.| A．ingenuity is essential for science fiction writers |
| B．imagination is the mother of invention |
| C．it takes patience for humans to realize their dreams |
| D．dreamers have always been interested in science fiction |
| A．It symbolized the American dream. |
| B．It was as urgent as racial equality. |
| C．It sounded very much like a dream. |
| D．It made an ancient dream come true. |
| A．It may not bring about immediate economic gains. |
| B．It cannot be realized without technological innovation. |
| C．It will not help the realization of racial and economic equality. |
| D．It cannot be achieved without a good knowledge of the other worlds. |
| A．Contradict. | B．Support. | C．Weaken. | D．Substitute for. |
Though problems are a part of our lives, it certainly doesn’t mean that we let them rule our lives forever. One day or the other, you’ll have to stand up and say — problem, I don’t want you in my life.
Of course, we’ve been fighting troubles ever since we were born. Problems with friends, parents, girlfriends, husbands, and children — the list goes on. Apart from these, the inner conflicts within ourselves work, too. These keep adding to our problems. Problems come in different shapes and colors and feelings.
But good news is that all problems can be dealt with. Now read on to know how to solve your problems.
Talk, it really helps. What most of us think is that our problem can be understood only by us and that no talking is going to help. But the truth is that when you talk about, you’re setting free the negative energies that have been gathering within you. Talking helps you move on and let go.
Write your problems. Having a personal diary can also be of huge help if you don’t want a real person to talk with. When you write down your problems, you’re setting free all the tension from your system. You can try throwing away the paper on which you wrote your problems. By doing this, imagine yourself throwing away the problems from your life.
Don’t lose faith and hope. No matter what you lose in life, don’t lose faith and hope. Even if you lose all your money, family ..., you should still have faith. With faith and hope, you can rebuild everything that you lose.
Your problems aren’t the worst. No matter what problem you get in life, there’re another one million people whose problems are huger than yours. Tell yourself: when they can deal with them, why can’t I? Your problems might just seem big and worse, but in reality they can be removed.
Go about and solve your problems because every problem, however big or small, always has a way out.
1. What is the text mainly about?
| A．How to find problems. |
| B．How to change problems. |
| C．How to live without problems. |
| D．How to deal with problems. |
| A．upset the readers |
| B．encourage the readers |
| C．laugh at the readers |
| D．please the readers |
| A．There are different kinds of problems in our life. |
| B．Problems are too difficult to deal with. |
| C．We have to fight problems in our whole life. |
| D．We have more and more problems. |
| A．you will be completely understood by others |
| B．you can find a way out from others |
| C．you will create another problem |
| D．you can live on more easily |
【推荐2】Animal keepers use the term enrichment to describe the introduction of environmental stimuli into the surroundings of caged animals. In recent years, “environmental enrichment” also known as behavioral enrichment, providing animals with challenges, opportunities, and stimulation that are species-appropriate, has grown more popular in zoos and aquariums. A latest study does, however, identify potential to “diversify the enrichment types being supplied and the species being examined.”
The study conducted by the University of Exeter and Sparsholt College, Hampshire, looked into whether zoo enrichment is based on evidence of what each species requires. It was discovered that this was true for specific animals as well as certain forms of enrichment, but the quantities of both could be larger, especially the samples of certain species of animals. “Based on our findings, we would encourage zoos to continue enrichment, but with a stronger emphasis on using available knowledge on what works for each species. Keepers should also consider what behaviors are being taught and whether there is evidence that this behavior is normal and good in the long run.” stated University of Exeter’s Dr. Paul Rose.
The research looked at a database of peer-reviewed works as well as two magazines for zoo workers. Almost 77 percent of the enrichment articles identified focused on mammals, with 11 percent on birds, 6 percent on considerable species, 4 percent on reptiles, and only a few on some other species. This emphasis on popular species may result in greater and higher-quality enrichment for some species than others. What’s more, in the case of mammals, the application of biological evidence to inform this enrichment was inconsistent.
There are many ways to enrich an animal’s surroundings such as adjusting animal care, forming social groups, and enhancing sensory stimulation. The purpose of any enrichment program should be to generate ideas for providing a species-appropriate stimulating environment that encourages positive behaviors while keeping in mind that both species and individuals will have varied demands.
1. What does the latest study mentioned in the passage want to figure out?| A．The real situation of zoo enrichment. | B．The final evidence of zoo enrichment. |
| C．The possible future of zoo enrichment. | D．The original purpose of zoo enrichment. |
| A．By giving a database. | B．By doing persuasion. |
| C．By discussing the data. | D．By presenting an example. |
| A．The lasting challenges and opportunities. |
| B．The space of the zoos and the keepers’ knowledge. |
| C．The enrichment types, the animal species and numbers. |
| D．The stimuli the keepers give and the articles the keepers write. |
| A．More Zoo Keepers Should Be Developed | B．Enrichment of Zoos Could Be Expanded |
| C．Articles on Enrichment Could Be Published | D．Environmental Enrichment Should Be Encouraged |
【推荐3】If someone created a flying machine capable of tracking you down by listening for your voice, you might be terrified. But what if you were trapped in ruins after a natural disaster and first responders couldn’t locate you? Maybe then a human-seeking drone (无人机) wouldn’t be such a terrible idea. That concept is the focus for engineers at German’s Fraunhofer FIE Institute, who’ve built a drone to find people by detecting (探测) human screams.
“The human-seeking drone would be ideal for post-disaster situations, such as earthquakes, hurricanes and wildfires”, said Macarena Varela, one of the lead engineers. “They could hover over an area that rescue crews have difficulty getting to and locate exactly where people may be trapped.”
Locating people by sound presents its share of challenges. An auditory (听觉的) system would need to distinguish human cries from sounds that often happen in nature, such as animal calls and wind. It might also need to recognize patterns associated with kicking, clapping or other ways people try to get the attention of rescue teams.
Engineers took those situations into account when building out their concept drone. They recorded themselves screaming, tapping and creating other noises that might be a sign of people in trouble. Then, they analyzed each sound frequency to find common signatures and used those to train artificial intelligence software. They also worked to remove the noise created by the drone and other environmental sounds.
Once the software part was complete, the team placed tiny digital microphones under the drone and used signal processing techniques that enabled them to track where human noises are coming from. The microphones also enhanced the volume and clarity of the speech. So far, they have conducted successful open field experiments, finding that the drone can estimate a victim’s location within a few seconds of picking up sound.
Next, they would like to add a higher frequency microphone to a drone to acquire more audio sound signals. The idea is to pick up noises from hundreds of meters away, Varela said. In the real world, victim's location data might one day be sent wirelessly to emergency crews carrying a tablet.
1. What can the auditory system do?| A．Recognize human cries. | B．Pick up sounds from far away. |
| C．Send victim’s location data to a tablet. | D．Improve the quality of human screams. |
| A．Effects. | B．Symbols. | C．Features. | D．Situations. |
| A．Its high speed of flying. | B．Its long working hours. |
| C．Its quick response to screams. | D．Its easy access to disaster scene. |
| A．AI Enables Drones to Give Better Performance |
| B．Human-seeking Drones Replace Rescue Crews |
| C．Rescuers Use Drones to Locate Disaster Survivors |
| D．Engineers Teach Drones to Hunt Human Screams |
