From our smartphones to our latest weaponry, the technology that underpins  modern life would be impossible without rare earth metals.  The importance of rare earths has only grown as emerging markets increase their demand for technologies made with it, as does the renewable energy industry. The 17 metallic elements are common in the earth-s crust, but the technique used to extract and refine them is labor-intensive, environmentally hazardous and increasingly costly.  Thomas Gradael,  a professor of geology and geophysics at the Yale School of Forestry Environmental Studies, explains that thecriticality" of rare earths was only recently understood after China, which dominates the world-s supply of the minerals, cut exports by 40% in 2010, citing concerns over how polluting the rare earth industry was. Along with colleagues at Yale, Gradael decided to investigate the metals used in modern technologies to determine if there were viable  substitutes."Twenty or thirty years ago electronics were being made with 11 different elements," explains Gradael.  "Today's computers and smartphones use something like 63 different elements." Their findings showed that there were no "readily apparent" substitutes for a metal that would not compromise on quality or performance. However increased mining for these scarce resources can have some nasty side effects for the environment. China, which has intensively mined for rare earths with little regulation, allowing it to dominate the global industry since 1990, has acknowledged the incredible environmental harm caused by the process.  "Excessive rare earth mining has resulted in landslides, clogged rivers, environmental pollution emergencies and even major accidents and disasters, causing great damage to people's safety and health and the ecological environment," read a white paper issued by the Chinese cabinet in June last year. Recycling metal has been advocated by some as a possible way of managing these precious resources-the European Parliament adopted a law curbing dumping... Which one of the following can be used in the blank? A) It is in China that rare earths are fully understood. B) Despite the name, rare earth metals are not in fact rare. C) There is a growing concern over the rare earth industry. D) Rare earth metals are difficult to collect though important.
B
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The Great Fire of London started in the very early hours of 2 September 1666. In four days it destroyed more than three-quarters of the old city, where most of the houses were wooden and close together. Over one hundred people became homeless, but only a few lost their lives. The fire started on Sunday morning in the house of the King's baker in Pudding Lane. The baker, with his wife and _ , was able to get out through a window into the roof. A strong wind blew the fire from the bakery into a small hotel next door. Then it spread quickly into Thames Street. That was the beginning. By eight o' clock three hundred houses were on fire. On Monday nearly a kilometer of the city was burning along the River Thames. Tuesday was the worst day. The fire destroyed many well-known buildings, old St Pauls and the Guildhall among them. Samuel Pepys, the famous writer, write about the fire, "People threw their things into the river. Many poor people stayed in their houses until the last moment. Birds fell out of the air because of the heat ." The fire stopped only when the King finally ordered people to destroy hundreds of buildings in the path of the fire. With nothing left to burn, the fire became weak and finally died out. After the fire, Christopher Wren, the architect , wanted a city with wider streets and fine new houses of stone. In fact, the streets are still narrow, but he did build more than fifty churches, among them the mew St Pauls. The fire caused great pain and loss, but after it London was a better place: a city for the future and not just of the past. The fire began in  _   . A) a hotel B) the palace C) Pudding Lane D) Thames Street
C
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Did you have a very strict teacher at school? I did. I'll never forget 'Mr. Strict'. If you didn't get your geography right, you would wish to run to the end of the earth to be far away from him. That tall man with a very loud voice knew how to frighten you and put the fear of God into you.  Nobody dared to be late for his class. No one dared to chat in his class no matter how boring the subject was. And not even the naughtiest pupil would dream of cheating in his tests. I thought about my old teacher when I read about a new government program in England to train former soldiers with no degrees to become a teacher. They can act either as secondary school subject teachers or as primary teachers. From next January those selected for the program will earn a salary and train on-the-job four days a week and one day at university. In two years they will be considered 'newly qualified teachers'. Education Minister David Laws said: "We know that our highly-skilled soldiers can inspire young people." He believes that values  in the army such as leadership, discipline , energy and teamwork would benefit children. But not everybody is happy with the government plans. Brian Lightman, from an organisation called the Association of School and College Leaders, thinks the training offered to the former soldiers who want to be teachers is not enough. Christine Blower, of the National Union of Teachers, believes that teachers need to understand how children develop. According to her, teachers need a high level of education themselves and thorough teacher training before they can educate the young. I'm not sure how much 'Mr. Strict' knew about child development. What I know is how happy he was when we did well. I'll never forget the broad smile on his face when I got a very high mark. My teacher was a soldier, but to me his smile was a medal for bravery in our war against ignorance ! According to Christine Blower,   _  . A) the English government should stop the program. B) teachers should often receive regular training C) teachers should know about child development D) only those who receive high education can be teachers
C
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Mars Was Not Always Bitterly Cold Scientists at the California Institute of Technology (Caltech) have reported evidence that Mars was warmer and wetter long ago than it is today.  The Caltech scientists say they have directly _ the temperature of Mars four billion years ago. At least, they established the surface temperature on part of the planet at that time. The researchers say it is the first such evidence to be discovered and presented. The Caltech scientists say carbonate  minerals formed on Mars at about eighteen degrees Celsius. They reached the finding after studying a meteorite  that had its beginnings near the Martian surface. Today, the average temperature on Mars is sixty-three degrees below zero Celsius. The finding was reported on the website of the National Academy of Sciences. Caltech Assistant Professor Woody Fischer helped to prepare the report. He says eighteen degrees Celsius is not especially cold or hot. He says this makes the finding extremely interesting. Knowing the temperature can give scientists an idea of the climate on Mars long ago. It can also help them decide whether the planet had liquid water. Spacecraft orbiting Mars have shown what appear to be rivers, lakebeds and mineral deposits. These pictures suggest that, at one time, water did flow there. Mars Rover vehicles and other spacecraft have confirmed the information. Caltech Geology Professor John Eiler was another writer of the report. He says knowing the temperature of Mars from long ago provides valuable information. It shows that early in the planet's history, at least part of Mars could support a climate like that of Earth. The meteorite the scientists examined is one of the oldest known rocks in the world. It is called the Allan Hills meteorite. Its name came from the place in Antarctica where it was found in 1984. The meteorite is believed to have blown loose from the Mars' surface when another space rock struck its "home." Where can we most probably read this passage? A) In a biography of scientists. B) In a geography magazine. C) In an environment report. D) In a science report.

D
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