Most people know precious gemstones (宝石) by their appearances. An emerald flashes deep green, a ruby seems to hold a red fire inside, and a diamond shines like a star. It’s more difficult to tell where the gem was mined, since a diamond from Australia or Arkansas may appear the same to one from the Democratic Republic of the Congo. However, recently, a team of scientists has found a way to identify a gemstone’s origin.
Beneath the surface of a gemstone, on the tiny level of atoms and molecules, lie clues to its origin. At this year’s meeting of the Geological Society of America in Minneapolis, Catherine McManus reported on a technique that uses lasers to clarify these clues and identify a stone’s homeland. McManus directs scientific research at Materialytics, in Killeen, Texas. The company is developing the technique. “With enough data, we could identify which country, which mining place, even the individual mine a gemstone comes from,” McManus told Science News.
Some gemstones, including many diamonds, come from war-torn countries. Sales of those “blood minerals” may encourage violent civil wars where innocent people are injured or killed. In an effort to reduce the trade in blood minerals, the U.S. government passed law in July 2010 that requires companies that sell gemstones to determine the origins of their stones.
To figure out where gemstones come from, McManus and her team focus a powerful laser on a small sample of the gemstone. The technique is called laser-induced breakdown spectroscopy. Just as heat can turn ice into water or water into steam, energy from the laser changes the state of matter of the stone. The laser changes a miniscule part of the gemstone into plasma, a gas state of matter in which tiny particles called electrons separate from atoms.
The plasma, which is superhot, produces a light pattern. (The science of analyzing this kind of light pattern is called spectroscopy.) Different elements produce different patterns, but McManus and her team say that gemstones from the same area produce similar patterns. Materialytics has already collected patterns from thousands of gemstones, including more than 200 from diamonds. They can compare the light pattern from an unknown gemstone to patterns they do know and look for a match. The light pattern acts like a signature, telling the researchers the origin of the gemstone.
In a small test, the laser technique correctly identified the origins of 95 out of every 100 diamonds. For gemstones like emeralds and rubies, the technique proved successful for 98 out of every 100 stones. The scientists need to collect and analyze more samples, including those from war-torn countries, before the tool is ready for commercial use.
Scientists like Barbara Dutrow, a mineralogist from Louisiana State University in Baton Rouge, find the technique exciting. “This is a basic new tool that could provide a better fingerprint of a material from a particular locality,” she told Science News. We learn from Paragraph 1 that __________________.
| A．an emerald and a ruby are names of diamonds. |
| B．it’s not difficult to tell where the gem was mined. |
| C．appearances help to identify the origin of gemstones. |
| D．diamonds from different places may appear the same. |
Why did the U.S. government pass law that requires companies selling gemstones to determine the origins of their stones?
| A．To look for more gemstones. |
| B．To encourage violent civil wars. |
| C．To reduce the trade in blood minerals. |
| D．To develop the economy. |
Which of the following facts most probably helps McManus and her team in identifying the origin of stones?
| A．Heat can turn ice into water or water into steam. |
| B．Gemstones from the same area produce similar light patterns. |
| C．Laser can changes a miniscule part of the gemstone into plasma. |
| D．Materialytics has already collected patterns from thousands of gemstones. |
From the last two paragraphs, what can be inferred about the laser technique?
| A．It is ready for commercial use. |
| B．People can use the new tool to find more gemstones. |
| C．It can significantly reduce the gemstones trade in blood minerals. |
| D．It will bring about a revolutionary change in identifying the origin of minerals. |
The author wrote this passage mainly to ________.
| A．tell us how to identify the origin of diamonds. |
| B．introduce a laser technique in identifying a stone’s origin |
| C．prove identifying the origin of gemstones are difficult |
| D．attract our attention to reducing trade in blood minerals |
They say love can cover a lot of crimes; yet never have I seen it more beautifully showed than in the life of a dog named Jessie. Jessie came into our lives at the age of six months. By that time he had already experienced the hard knocks of life. He was found abandoned on the side of the road, where we adopted him and took him home.
From the beginning, it was obvious that Jessie was traumatized (受精神创伤的). He was afraid of everything: the car, the doors, the stairs, and just about everything else. We couldn’t foresee where Jessie’s fear would take us.
Jessie was with us for about six months, when we became foster parents to a mixed-breed young dog. Jessie did not like her at all. We all lived in a nervous co-existence, until dinnertime. Within moments a food fight erupted between Jessie and this foster child.
It all happened so fast, and I was in the middle. My husband managed to get in between the two dogs, grabbing Jessie by his collar. Jessie screamed all the way down the hall and into the bedroom. I, quickly put the foster dog into her own bedroom and hurried down the hall. The crashing I heard in the bedroom, scared me to death. But nothing prepared me for the scene I witnessed as I opened the bedroom door.
There was my husband, on top of a terrified Jessie, holding back his head. Blood dripped from my husband’s arm. To tell you the truth, as I was sitting beside my husband in the emergency room, I just didn’t know what to do with Jessie. I was so angry at that dog.
Day after day, week after week, however, my husband faithfully trained the dog that others would have put down. As his arm healed over the next months, something rare and beautiful began to take place. Jessie, under my husband’s gentle persuasion, began to understand and obey. And Jessie adored him. I could see, that although the tempest had ruled Jessie’s former life, affirmation and love had calmed the storm.Before being adopted by the writer, Jessie had _______.
| A．suffered a lot |
| B．Lived a happy life |
| C．lived on the road half a year |
| D．often fought against other dogs |
Paragraph 2 shows that the writer was ________.
| A．happy | B．disappointed |
| C．angry | D．worried |
It can be inferred from the text that the writer’s husband’s arm bled because of _________.
| A．his own behavior |
| B．the writer’s fault |
| C．Jessie’s bite |
| D．The new foster dog |
What would be the best title for the text?
| A．A Dog Named Jessie |
| B．Love Calmed the Storm |
| C．Conflicts Between Dogs |
| D．Fights Between Man and Dog |
Teachers and parents usually pay attention to the pictures when they read storybooks to preschool children. But a new study suggests that paying attention to the words and letters on the page may lead to better readers.
The two-year study compared children who were read to this way in class with children who were not. Those whose teachers most often discussed the print showed clearly higher skills in reading, spelling and understanding. These results were found one year and even two years later.
Shayne Piasta, an assistant professor of teaching and learning at Ohio State University, was an author of the study. She says most preschool teachers would find this method manageable and would need only a small change in the way they teach. They already read storybooks in class. The only difference would be increased attention to the printed text.
Ms Piasta says if you get children to pay attention to letters and words, it makes sense that they will do better at word recognition and spelling. But she says research suggests that very few parents and teachers do this in a systematic(系统的) way.
More than 300 children aged four and five were observed in classrooms in Ohio and Virginia. The children came from poor families and were below average in their language skills. This put them at risk of reading problems later. For 30 weeks, the children took part in a program called Project STAR. It tests the short-term and long-term results of reading regularly to preschool children in their classrooms.
There’re different ways that adults can talk to children about print. They can point to a letter and discuss it, and even trace the shape with a finger. They can point out a word, “This is a ‘dog’.” They can discuss how the words tell the story. And they can talk about the organization of the print—for example, showing how words are written left to right in English.According to the text, Shayne Piasta _______.
| A．worked in a middle school |
| B．didn’t attend the research at all |
| C．liked kids to be educated through words |
| D．hoped to increase kids’ interest through pictures |
According to the text, Project STAR ____.
| A．focused on adults’ education |
| B．was to study reading results |
| C．was mainly conducted at home |
| D．tested kids with good reading skills |
What is the last paragraph mainly about?
| A．Why words have meanings. |
| B．Different expressions of words. |
| C．How words are spelled differently. |
| D．Ways of teaching about print. |
The text may appear in ____.
| A．Child Development |
| B．Daily Technology |
| C．International Affairs |
| D．Health Development |
Wugging, or web use giving, describes the act of giving to charity at no cost to the user. By using Everyclick.com, which is being added to a number of university computers across the UK, students can raise money every time they search, but it won’t cost them a penny.
Research shows that students are extremely passionate(热情的)about supporting charity（慈善）--- 88％of full time students have used the Internet to give to charity. This figure is high because this age group is often the least likely to have their own income. 19％ of 22 to 24 year olds have short-term debts of more than￡5，000. With rising personal debt levels in this age group, due to university tuition fees or personal loans and a lack of long-term savings, traditional methods of donating to charity are often not possible.
Beth Truman, a 21year old recent university graduate has used Everyclick.com to donate to her chosen charity, the RSPCA, for two years and has seen the “wugging” movement grow in popularity with students. “When you’re at university you become more socially aware, but it's sometimes hard to give to others when you have little money yourself,” says Beth. “Wugging is great for people in this age group as it allows them to use the technology on a daily basis to give to charity, without costing them a single penny.”
Wugging is perfect for people who want to be more socially aware and supportive but don’t feel they have the means to do so. Students using the web can raise money for causes they care about without costing them anything in terms of time or money, and charities get a valuable source of funding.
Everyclick.com works like any other search engine, allowing users to search for information, news and images but users can decide which of the UK’s 170,000 charities they would like to support through their clicks. Everyclick.com then makes monthly payments to every registered charity. Launched in June 2005, Everyclick.com is now the eighth largest search engine and one of the busiest charity websites in the UK. According to the passage, “wugging” is actually a_______.
| A．website | B．charity-related action |
| C．school organization | D．student movement |
How does Beth Truman think of the “wugging” movement?
| A．It makes Everyclick.com popular in the UK. |
| B．It makes giving to charity easy. |
| C．It results in students being more social awareness. |
| D．it stresses the importance of charity in people’s daily lives. |
From the passage, we can conclude that _______.
| A．most full time students contribute to charity on the Internet every day |
| B．Everyclick.com helps students pay for the college education |
| C．“Wugging” is a win-win idea for both students and charities |
| D．Everyclick.com is the most successful search engine in the UK |
What would be the best title for this passage?
| A．“Wugging”, a New Popular Term（术语）on the Internet |
| B．British People Show Strong Interest in Charity |
| C．More Britain Charities Benefit from the Internet |
| D．Students Raise Money for Charity by “wugging” |
Many of us believe that a person’s mind becomes less active as he grows older. But this is not true, according to Dr Jarvik, professor of psychiatry at the University of California. She has studied the mental functioning of aging persons for several years. For example, one of her studies concerns 136 pairs of twins (双胞胎), who were first examined when they were already 60 years old. As Dr Jarvik continued the study of the twins into their 70s and 80s, their minds did not generally decline (衰弱) as was expected.
However, there was some decline in their psycho-motor speed. This means that it took them longer to finish mental tasks than it used to. But when speed was not a factor, they lost very little intellectual (智力的) ability over the years. In general, Dr Jarvik’s studies have shown that there is no decline in knowledge or reasoning ability. This is true not only with those in their 30s and 40s, but with those in their 60s and 70s as well.
It is true that older people themselves often complain that their memory is not as good as it once was. However, much of what we call “loss of memory” is not that at all. There usually was incomplete learning in the first place. For example, the older person perhaps had trouble hearing, or poor vision, or was trying to learn the new thing at too fast a speed. In the cases where the older person’s mind really seems to get worse, it is not necessarily a sign of decline due to old age. Often it is simply a sign of a sad emotional state. This passage is mainly about _______.
| A．what caused mental decline |
| B．a new discovery about mental decline |
| C．the difference between middle-aged and older persons |
| D．how Dr Jarvik studied mental functioning of the twins |
The word “psychiatry” in paragraph 1 most probably means _______.
| A．the study of diseases of the mind |
| B．the study of physical diseases |
| C．the study of twins’ growth |
| D．the study of human behavior |
More often than not, what we call mental decline is actually a sign of _______.
| A．a worsening state of health | B．old age |
| C．nervous tension | D．a state of unhappiness |
I made a pledge(发誓) to myself on the way down to the vacation beach cottage. For two weeks I would try to be a loving husband and father.
The idea had come to me as I listened to a talk on my car radio. The speaker was quoting a Biblical (圣经的) passage about husbands being thoughtful of their wives. Then he went on to say, “Love is an act of will. A person can choose to love.” To myself, I had to admit that I had been a selfish husband. Well, for two weeks that would change.
And it did. Right from the moment I kissed Evelyn at the door and said, “That new yellow sweater looks great on you.”
“Oh, Tom, you noticed,” she said, surprised and pleased. Maybe a little puzzled.
After the long drive, I wanted to sit and read. Evelyn suggested a walk on the beach. I started to refuse, but then I thought, “Evelyn’s been alone here with kids all week and now she wants to be alone with me.” We walked on the beach while the children flew the kites.
So it went. Two weeks of not calling the Wall Street firm where I am a director; a visit to the shell museum though I usually hate museums. Relaxed and happy, that’s how the whole vacation passed. I made a new pledge to keep on remembering to choose love.
There was one thing that went wrong with my experiment, however. Evelyn and I still laugh about it today. On the last night at our cottage, preparing for bed, Evelyn stared at me with the saddest expression. “What’s the matter?” I asked her.
“Tom, ” she said in a voice filled with sadness, “do you know something I don’t?”
“What do you mean?”
“Well…..that checkup(体检) I had several weeks ago….. our doctor ….. did he tell you something about me? Tom, you’ve been so good to me….. am I dying ?”
It took a moment for it all to sink in. Then I burst out laughing.
“No, honey,” I said, wrapping her in my arms. “You’re not dying; I’m just start to live.”The writer thought he was a _______ husband in the past.
| A．lovely | B．loyal | C．strict | D．selfish |
From the story we may infer that Tom drove to the beach cottage _______.
| A．with his family | B．with Evelyn | C．alone | D．with his children |
The underlined words “one thing” in the text refer to the fact that _______.
| A．he praised her sweater, which puzzled her |
| B．she insisted on visiting a museum, which he hated |
| C．he knew something about her illness but didn’t tell her |
| D．he was so good to her that she thought she must be dying |