1 There's a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years—exactly the same period as between ice ages on Earth. So says a physicist who has created a computer model of our star's core.
2 Robert Ehrlich of
George Mason University in Fairfax, Virginia, modelled the effect
of temperature fluctuations in the sun's interior. According to the standard view, the temperature of the sun's core is held constant by the opposing pressures
of gravity and nuclear fusion. However, Ehrlich believed
that slight variations should be possible.
3 He took as his starting point the work of Attila Grandpierre of the
Konkoly Observatory of the Hungarian Academy of Sciences. In , Grandpierre and a collaborator,
ágoston,calculated that magnetic fie lds in the
sun's core could produce small instabilities in the solar plasma. These instabilities
would induce localised oscillations
4 Ehrlich's model shows that whilst most of these oscillations cancel each other out,
some reinforce one another and become
long-lived temperature variations. The favoured frequencies allow the sun's core temperature to oscillate a round its average temperature of 13.6 million kelvin in
cycles lasting either 100,000 or
41,000 years. Ehrlich says
that random interactions within the sun's magnetic field could flip the fluctuations from one cycle length to the other.
5 These two timescales are instantly recognisable to anyone familiar with Earth's ice ages: for the past million years, ice ages have occurred roughly every 100,000 years. Before that, they occurred roughly every 41,000 years.
6 Most scientists believe that the ice ages are the result
of subtle changes in Earth's orbit, known as the Milankovitch cycles. One such cycle describes the way Earth's orbit gradually changes shape from a circle to
a slight ellipse and back again roughly every 100,000 years. The theory says this alters the amount of
solar radiation that Earth receives, triggering the ice ages. However,
a persistent problem with this theory has been its inability to explain why the ice ages changed frequency a million years ago.
7 "In Milankovitch, there is certainly no good idea why
the frequency should change from one to another," says Neil Edwards, a climatologist at the Open University in Milton Keynes, UK. Nor is
the transition problem the only one the Milankovitch theory faces. Ehrlich and other critics claim that the temperature variations caused by Milankovitch cycles are simply not big enough to drive ice ages.
8 However, Edwards believes the small changes in solar heating produced by Milankovitch cycles are then amplified by feedback
雅思阅读模拟试题:音乐 Background music may seem harmless, but it can have a powerful effect on those who hear it. Recorded background music first found its way into factories, shop and restaurants in the US. But it soon spread to other arts of the world. Now it is becoming increasingly difficult to go shopping or eat a meal without listening to music. To begin with, “ muzak ” (音乐广播网) was intended simply to create a soothing (安慰) atmosphere. Recently, however, it’s become big business –thanks in part to recent research. Dr. Ronald Milliman, an American marketing expert, has shown that music can boost sales or increase factory production by as much as a third. But, it has to be light music. A fast one has no effect at all on sales. Slow music can increase receipts by 38%. This is probably because shoppers slow down and have more opportunity to spot items they like to buy. Yet, slow music isn’t always answered. https://www.sodocs.net/doc/6112775403.html,liman found, for example, that in restaurants slow music meant customers took longer to eat their meals, which reduced overall sales. So restaurants owners might be well advised to play up-tempo music to keep the customers moving – unless of course, the resulting indigestion leads to complaints! ( )1. The reason why background music is so popular is that ______. A. it can have a powerful effect on those who hear it B. it can help to create a soothing atmosphere C. it can boost sales or increase factory production everywhere D. it can make customers eat their meals quickly ( )2. Background music means ________. A. light music that customers enjoy most B. fast music that makes people move fast C. slow music that can make customers enjoy their meals D. the music you are listening to while you are doing something ( )3. Restaurant owners complain about background music because ______. A. it results in indigestion B. it increases their sales C. it keeps customers moving D. it decreases their sales ( )4. The word “ up-tempo music” probably means_____. A.slow music B.fast music C.light music D.classical music
1 / 11 剑桥雅思8阅读解析 READING PASSAGE 2 You should spend about 20 minutes on Questions 14-26, which are based on Reading Passage 2 below. The Nature of Genius There has always been an interest in geniuses and prodigies. The word 'genius', from the Latin gens (= family and the term 'genius', meaning 'begetter', comes from the early Roman cult of a divinity as the head of the family. In its earliest form, genius was concerned with the ability of the head of the family, the paterfamilias, to perpetuate himself. Gradually, genius came to represent a person's characteristics and thence an individual's highest attributes derived from his 'genius' or guiding spirit. Today, people still look to stars or genes, astrology or genetics, in the hope of finding the source of exceptional abilities or personal characteristics. The concept of genius and of gifts has become part of our folk culture, and attitudes are ambivalent towards them. We envy the gifted and mistrust them. In the mythology of giftedness, it is popularly believed that if people are talented in one area, they must be defective in another, that intellectuals are impractical, that prodigies burn too brightly too soon and burn out, that gifted people are eccentric, that they are physical weaklings, that there's a thin line between genius and madness, that genius runs in families, that the gifted are so clever they don't need special help,
Next Year Marks the EU's 50th Anniversary of the Treaty A. After a period of introversion and stunned self-disbelief，continental European governments will recover their enthusiasm for pan-European institution-building in . Whether the European public will welcome a return to what voters in two countries had rejected so short a time before is another matter. B. There are several reasons for Europe’s recovering self-confidence. For years European economies had been lagging dismally behind America (to say nothing of Asia)， but in the large continental economies had one of their best years for a decade， briefly outstripping America in terms of growth. Since politics often reacts to economic change with a lag，’s improvement in economic growth will have its impact in ， though the recovery may be ebbing by then. C. The coming year also marks a particular point in a political cycle so regular that it almost seems to amount to a natural law. Every four or five years， European countries take a large stride towards further integration by signing a new treaty： the Maastricht treaty in 1992， the Treaty of Amsterdam in 1997， the Treaty of Nice in . And in they were supposed to ratify a European constitution， laying the ground for yet more integration—until the calm rhythm was rudely shattered by French and Dutch voters. But the political impetus to sign something every four or five years has only been interrupted，not immobilised， by this setback. D. In the European Union marks the 50th anniversary of another treaty—the Treaty of Rome， its founding charter. Government leaders have already agreed to celebrate it ceremoniously， restating their commitment to “ever closer union” and the basic ideals of European unity. By itself， and in normal circumstances， the EU’s 50th-birthday greeting to itself would be fairly meaningless， a routine expression of European good fellowship. But it does not take a Machiavelli to spot that once governments have signed the declaration (and it seems unlikely anyone would be so uncollegiate as to veto
2019年雅思考试巩固模拟试题及答案1 Next Year Marks the EU's 50th Anniversary of the Treaty A. After a period of introversion and stunned self-disbelief, continental European governments will recover their enthusiasm for pan-European institution-building in 2007. Whether the European public will welcome a return to what voters in two countries had rejected so short a time before is another matter. B. There are several reasons for Europe’s recovering self-confidence. For years European economies had been lagging dismally behind America (to say nothing of Asia), but in 2006 the large continental economies had one of their best years for a decade, briefly outstripping America in terms of growth. Since politics often reacts to economic change with a lag, 2006’s improvement in economic growth will have its impact in 2007, though the recovery may be ebbing by then. C. The coming year also marks a particular point in a political cycle so regular that it almost seems to amount to a natural law. Every four or five years, European countries take a large stride towards further integration by signing a new treaty： the Maastricht treaty in 1992, the Treaty of Amsterdam in 1997, the Treaty of Nice in 2001. And in 2005 they were supposed to ratify a European constitution, laying the ground for yet more integration—until the calm rhythm was rudely shattered by French and Dutch voters. But the political impetus to sign something every four or five years has only been interrupted, not immobilised, by this setback. D. In 2007 the European Union marks the 50th anniversary of another treaty—the Treaty of Rome, its founding charter. Government leaders have already agreed to celebrate it
剑桥雅思8阅读Test1Passage3原文翻译-心灵感应 解析查看，请点击：剑桥雅思8阅读Test1Passage1原文+答案解析 人类可否只通过思想进行沟通交流? 一百多年来,关于心灵感应的话题在科学界产生很大意见分歧,时至今日,它依然在学界精英中引起激烈辩论。 自上个世纪70年代以来，在世界各大高校和科研院所，超心理学者们冒着被同行嘲笑和怀疑的风险，将关于心灵感应的各种不同说法进行严格的科学实验，其结果及其启示即使在研究者本身中，也引发了很大争议。 有些科学家认为，实验结果提供了强有力证据，可以证明心灵感应是真实存在的。另一些超心理学家则相信，该研究虽试图用科学证据证明心灵感应存在，却并未取得成功，相关研究也都处在失败的边缘。不过无论是怀疑者还是倡导者都同意一点，即迄今最有力的证据来自于“ganzfeld”实验。该实验名称来自德语，意思是“全域”。通过冥想心灵感应实验者的报告，超心理学家怀疑，可能因为人们之间传递的“信号”过于模糊，以至于很容易被正常的脑波活动所覆盖。如果这样的话，当人们身处一个伴有灯光和音响的温暖轻松的环境，经历冥想般的宁静，会更容易感知此类信号。 该实验几乎满足了所有的条件。参加者待在密封的房间里，坐着柔软的躺椅，听着轻松的音乐，眼睛被特殊的过滤器覆盖，只看见柔和的粉色光。早期的实验主要涉及选图。先从一个大型图库中任意选出四张图片，再让实验者指认其中一张。具体操作步骤是，作为“发送人”的实验者努力将一张图通过思维传给密封房间内的“接收人”。当传送结束后，“接收人”需从四张图中选出哪一张才是刚刚被传送的图。如果是随便猜测,可达到25%的命中率。然而，如果心灵感应真的存在，命中率就应该更高。1982年，心灵感应研究的先行者之一，美国超心理学家查尔斯·荷诺顿(Charles Honorton)分析了这些早期实验的结果。结果证明典型的命中率要高于30%。虽然比例高不了多少，但统计测试表明，结果已不完全是偶发几率。 “ganzfeld”实验似乎可以证明心灵感应是真的存在。但是在这个论据本身有个不足之处，在很多传统科学领域中也常常被忽视：不能因为排除了偶然几率的存在，就能证明心灵感应就是真实存在的。很多其他方法也可以得出正向的结果：既有图片线索偶然传递给接受者的感官泄露，也有彻底的欺骗。作为回应，研究人员回顾了截至1985年的全部ganzfeld 研究，结果显示80%的研究提供了重要的统计数据。不过，他们也同意,实验中太多的因素都可导致正向结果，因此他们制定了清单，希望在未来研究中可采用新的标准。 此后，许多研究人员转向autoganzfeld 测试。这种自动化技术使用电脑来完成关键任务如随机选择图像。通过最大限度地减少人为参与，尽量降低错误结果出现的风险。1987年，荷诺顿(Honorton)使用了“荟萃分析”，这是一种可以从系列研究中找出整体结果的新型统计方法。他对数以百计的 autoganzfeld 实验结果进行了分析,虽然没有以前那样引人注目，结果依然令人印象深刻。 然而，单独的ganzfeld 实验研究彼此间缺乏一致性，这让一些超心理学家感到十分困扰。心灵感应拥护者们指出，如果要求每一项研究都得出满意结果，起码忽略了一个基本的统计学事实：需要大量的样本才能得出少量的结果。如果像目前的结果显示那样,偶然几率是 25%,而心灵感应存在的几率只略高于它，真正的证据就不可能由一个典型的约40人参加的ganzfeld 实验所提供：因为样本集合不够大,数目不够多。只有用“荟萃分析”将多项实验研究结合起来，心灵感应存在的证据才会由模糊变得清晰。而这貌似也是研究者们所正在追寻的。
2019年雅思阅读模拟试题：流程图题(1) BAKELITE The birth of modern plastics In 1907, Leo Hendrick Baekeland, a Belgian scientist working in New York, discovered and patented a revolutionary new synthetic material. His invention, which he named 'Bakelite,’was of enormous technological importance, and effectively launched the modern plastics industry. The term 'plastic' comes from the Greek plassein, meaning 'to mould'. Some plastics are derived from natural sources, some are semi-synthetic (the result of chemical action on a natural substance), and some are entirely synthetic, that is, chemically engineered from the constituents of coal or oil. Some are 'thermoplastic', which means that, like candlewax, they melt when heated and can then be reshaped. Others are 'thermosetting'： like eggs, they cannot revert to their original viscous state, and their shape is thus fixed for ever. Bakelite had the distinction of being the first totally synthetic thermosetting plastic. The history of today's plastics begins with the discovery of a series of semi-synthetic thermoplastic materials in the mid-nineteenth century. The impetus behind the development of these early plastics was generated by a number of factors—immense technological progress in the domain of chemistry, coupled with wider cultural changes, and the pragmatic need to find acceptable substitutes for dwindling supplies of 'luxury' materials such as tortoiseshell and ivory.
2019年雅思IELTS考试备考资料模拟试题及答案14 The nervous system of vertebrates is characterized by a hollow, dorsal nerve cord that ends in the head region as an enlargement, the brain. Even in its most primitive form this cord and its attached nerves are the result of evolutionary specialization, and their further evolution from lower to higher vertebrate classes is a process that is far from fully understood. Nevertheless, the basic arrangements are similar in all vertebrates, and the study of lower animals gives insight into the form and structure of the nervous system of higher animals. Moreover, for any species, the study of the embryological development of the nervous system is indispensable for an understanding of adult morphology. In any vertebrate two chief parts of the nervous system may be distinguished. These are the central nervous system (the nerve cord mentions above), consisting of the brain and spinal cord, and the peripheral nervous system, consisting of the cranial, spinal, and peripheral nerves, together with their motor and sensory endings. The term "autonomic nervous system" refers to the parts of the central and peripheral systems that supply and regulate the activity of cardiac muscle, smooth muscle, and many glands. The nervous system is composed of many millions of nerve and glial cells, together with blood vessels and a small amount of connective tissue. The nerve cells, or "neurons", are characterized by many processes and are specialized in that they exhibit to a great degree the phenomena of irritability and conductivity. The glial cells of the central nervous system are supporting cells collectively termed
雅思考试全题模拟试题(1) Listening TIME ALLOWED: 30 minutes NUMBER OF QUESTION: 40 Instruction You will hear a number of different recordings and you will have to answer questions on what you hear. There will be time for you to read the instructions and questions, and you will have a chance to check you work. All the recordings will be played ONCE only. The test is in four sections. Write your answers in the listening question booklet. At the end of the test you will be given ten minutes to transfer your answers to an answer sheet. Now turn to Section 1 on page 2. SECTION 1 Question1-9 Question 1-6 Listen to conversation between friend and the housing officer and complete the list below. Write NO MORE THAN THREE WORDS OR NUMBERS for each answer. HOUSING LIST HOUSING LIST Address Number of rooms Price per week Additional information Mr. J Devenport 82Salisbury Road Brighton BN 16 3 AN Tel 01273 884673 2 bedrooms sitting room kit. bath Example ￡120 Unfurnished Mrs E.S. Jarvis2Wicken Street Brighton BN 15 4JH Tel 01273 771621 (1) sitting room kit.bath (2) First floor Mrs. E.C. Sparshott 180Silwood Road Brighton BN 14 9RY Tel (3) 2 large rm/s shared kit and bath ￡35 Nice area (4) Mr A Nasiry 164 Preston Road Brighton BN5 7RT Tel 01273 703865 large bedroom sitting room with kitchenette.bath. (5) Ground floor Central (6) 2 harrow Road Brighton BN9 9HK Tel 01273 745621 2 large rooms kit bath ￡86 No pets Questions 7-9 Write NO MORE THAN THREE WORDS for each answer 7.When is the accommodation available? 8.Where is the telephone? 9.How is the flat heated? SECTION 2 Questions 10-20
剑桥雅思口语真题解析 Part 1: 1.1姓名 1. What’s your full name? 2. Can I have your name, please? 3. Are there any special meanings of your name? 4. Do you like your name? Why? 5. Do Chinese people like changing their names? 6. What kind of people in China like changing their names? 7. Is there any rule for Chinese people giving names to their children? 1.2故乡 My hometown is Guangzhou. It is the capital of Guangdong province in the southwest of China. It is a large industrial city. It is close to Hong Kong so a lot of the industries involve trade and retail. It is also a finance area. The people in Guangzhou are very genial and helpful, also are very easy to get around. If you lose your way and ask someone, he will give you the direction immediately, he can also give you a hand if you are in trouble. By the year 2011, it is believed that my hometown Guangzhou has become the economic center of China. 2. Where is it located? 3. How about the climate in your hometown? Which season do you like? In my hometown Guangzhou, the four seasons are not evident, which only has spring and summer. It is too hot in the summer and it is also humid in the winter. I like summer better, for we will go swimming and start our outdoor activities in the summer, it gives us pretty environment, which full of various kinds of colors. Another reason is that it is suitable for traveling around. 4. How about the people in your hometown? The people in my hometown Guangzhou are very genial and helpful, also are very easy to get around. People will always give you a hand with things. If you lose your way and ask someone, he will give you the direction immediately, he can also give you a hand if you are in trouble. 5. What do most people do in your hometown? 6. Oh yes. Even though Guangzhou is very modern, it has some interesting temples and streets. There is one called the Temple of Six Banyan Trees and it was built about 1500 years ago. There is also a famous cultural and commercial street in Guangzhou called Beijing Road. In this street, you can not only see a historic exhibition about different years roadbed, which has more than thousand histories, but also has many business shops sale almost all kinds of things. Besides, you can taste traditional snacks and refreshments or experience temples with /unusual special architectural style nearby. Anyway, it is an interesting place so worth to visit! 7. How about the style of the building in your hometown? 8. What is one of the greatest changes having taken place over the years? 9. What problems still exist in your hometown? 10. How to improve the situation in your hometown? 11. Where is Chinese population mainly distributed? 12. What changes have occurred in people’s dwelling? 1.3学习 1. Are you an employee or a student? (Are you working or studying?) 2. What is your major?
雅思阅读模拟试题精选 1. Washing， brushing and varnishing fossils — all standard conservation treatments used by many fossil hunters and museum curators alike —vastly reduces the chances of recovering ancient DNA. 2. Instead， excavators should be handling at least some of their bounty with gloves， and freezing samples as they are found， dirt and all， concludes a paper in the Proceedings of the National Academy of Sciences today. 3. Although many palaeontologists know anecdotally that this is the best way to up the odds of extracting good DNA， Eva-Maria Geigl of the Jacques Monod Institute in Paris， France， and her colleagues have now shown just how important conservation practices can be. This information， they say， needs to be hammered home among the
Section I Words A.Match the words with the same meaning.W rite down the letters on you answer sheet. (1(1’’*6) 1.epidermic 2.motivate 3.assume 4.appealing 5.controversy 6expertise A.skill or knowledge in a particular area B.dispute,argument C.attractive D.an outbreak of a contagious disease that spreads rapidly and widely E.to provide with an incentive;impel . F.to take for granted,suppose B.Fill in the blanks with proper forms of words given in the box,one word can be used more than once.(1(1’’*10) evolve prepare propose minimum peer through cheat weep address exploit except 1.Not surprisingly,his was not well received,even though it seemed to agree with the scientific information available at the time.. 2.The little girl with disappointment when she learned that her favourite Barbie Dolls were sold out. 3.The price is her,she refuses to lower it any further. 4.Apes,monkeys and many other primates have fairly elaborate systems of calls for communicating with other members of their species. 5.Some melodies are quite manipulative,working on our emotions very effectively,and composers have often this to the full. 6.I realized I’d been when I saw the painting on sale for half the price I paid for it. 7.To this problem,Counter Intelligence built a kitchen of its own and started making gagets to fill it with. 8.Most birds don’t have a good sense of smell,but fish-eaters such as petrels and shearwaters are significant. 9.Why bother a clear door,when you can put a camera in the oven to broadcast snapshots of the activities in the oven to a screen in another room? 10.Exploration will allow us to make suitable for dealing with any dangers that we might face,and we may be able to find physical resources such as minerals. SectionⅡ.Translation A.Translate the following sentences into English.(3(3’’*5) 1.Despite the hardship he encountered,Mark never (放弃对知识的追求) 2.由于缺乏对这种病的了解，许多人依然认为HIV受害者都是自作自受。(owing to; ignorance)