This morning, a Virgin Atantin 747 Jumbo Jet became the first commercial airplane to fly on biofuel. The short flight from London to Amsterdam used a blend of 20% babassu(棕榈) oil mixed with 80% conventional jet fuel.
What was really exciting about the flight was the fact that the engine did not have to be altered in any way for the biofuel to work While this is a great initial step in trying to reduce CO2(carbon-dioxide)emissions(排放)from airplanes. there are a lot of hurdles (障碍)that still need to be overcome.
First and foremost, unlike the normal fuel used to run airplanes (known as Jet A),biofuel freezes at high altitudes. Also, Jet‘A’fuel burns consistently (at the same pace),which means it provides a safe and reliable fuel for long flights--engineers are not sure if biofuel will be able to do the same.
The biggest hurdle to a full biofuel switch is our ability to be able to grow enough crops that can be converted to biofuel. There are two concerns that scientists have in this matter – the first is that the land to grow the extra crops will come from clearing more of our forests and the second is that since it competes with what we eat, the price of food will go up.
However, Richard Branson of Virgin Airlines, envisions that if biofuel starts to replace oil on a greater basis, it will be manufactured from algae（藻类）produced in sewage treatment plants, not from food sources.
Birgin Airlines is not the only one trying to look for alternative fuel sources. Earlier this year, an Airbus A380 used another alternative fuel－a man-made mix of gas-to-liquid, in one of its four engines. The flight was tested by Rolls Royce (manufacturer of jet engines), in partnership with Shell (an oil company). Rolls Royce is also working with Air New Zealand on a similar project.
While a complete switch to alternative fuel may take years, it is very encouraging to see airlines, oil companies and airplane manufacturers all coming together to try to make it happen!．Why does Virgin Airlines try to replace normal fuel with biofuel?
| A．To cut down the flight cost of the company. |
| B．To remove some hurdles for the biofuel to work. |
| C．To reduce CO2 emissions from airplanes. |
| D．To test plane engines on biofuel. |
．Which is NOT true for a full biofuel switch of airplanes?
A Biofuel cannot run for long flights.
B．Biofuel cannot work at high altitudes.
C．Man has not enough land to grow extra crops for biofuel.
D．It’s not easy for sewage treatment plants to manufacture biofuel.．One of the hurdles to be overcome for a full biofuel switch is to .
| A．alter the engine for airplanes |
| B．make biofuel burn consistently |
| C．open more land to grow more crops |
| D．develop sewage treatment plants |
．We can infer from the last paragraph that .
| A．there is a long way to go for a complete switch to alternative fuel |
| B．it won’t be long before alternative fuel comes into use |
| C．airlines, oil companies and airplane manufacturers are reliable |
| D．alternative fuel has a bright future |
．Which of the following can best serves as the title of this passage?
| A．Biofuel-Alternative Fuel Sources. |
| B．The First Commercial Flight Powered by Biofuel. |
| C．How to Reduce CO2 Emissions from Airplanes. |
| D．Vigin Airlines Trying to Alter Fuel Sources. |
Decision-making under Stress
A new review based on a research shows that acute stress affects the way the brain considers the advantages and disadvantages, causing it to focus on pleasure and ignore the possible negative (负面的) consequences of a decision.
The research suggests that stress may change the way people make choices in predictable ways.
“Stress affects how people learn,” says Professor Mara Mather. “People learn better about positive than negative outcomes under stress.”
For example, two recent studies looked at how people learned to connect images(影像) with either rewards or punishments. In one experiment, some of the participants were first stressed by having to give a speech and do difficult math problems in front of an audience; in the other, some were stressed by having to keep their hands in ice water. In both cases, the stressed participants remembered the rewarded material more accurately and the punished material less accurately than those who hadn’t gone through the stress.
This phenomenon is likely not surprising to anyone who has tried to resist eating cookies or smoking a cigarette while under stress –at those moments, only the pleasure associated with such activities comes to mind. But the findings further suggest that stress may bring about a double effect. Not only are rewarding experiences remembered better, but negative consequences are also less easily recalled.
The research also found that stress appears to affect decision-making differently in men and women. While both men and women tend to focus on rewards and less on consequences under stress, their responses to risk turn out to be different.
Men who had been stressed by the cold-water task tended to take more risks in the experiment while women responded in the opposite way. In stressful situations in which risk-taking can pay off big, men may tend to do better, when caution weighs more, however, women will win.
This tendency to slow down and become more cautious when decisions are risky might also help explain why women are less likely to become addicted than men: they may more often avoid making the risky choices that eventually harden into addiction.We can learn from the passage that people under pressure tend to ______.
| A．keep rewards better in their memory |
| B．recall consequences more effortlessly |
| C．make risky decisions more frequently |
| D．learn a subject more effectively |
According to the research, stress affects people most probably in their ______.
| A．ways of making choices | B．preference for pleasure |
| C．tolerance of punishments | D．responses to suggestions |
The research has proved that in a stressful situation, ______.
| A．women find it easier to fall into certain habits |
| B．men have a greater tendency to slow down |
| C．women focus more on outcomes |
| D．men are more likely to take risks |
Peanuts to This
Proudly reading my words, I glanced around the room, only to find my classmates bearing big smiles on their faces and tears in their eyes. Confused, I glanced toward my stone-faced teacher. Having no choice, I slowly raised the report I had slaved over, hoping to hide myself. “What could be causing everyone to act this way?”
Quickly, I flashed back to the day Miss Lancelot gave me the task. This was the first real talk I received in my new school. It seemed simple: go on the Internet and find information about a man named George Washington. Since my idea of history came from an ancient teacher in my home country, I had never heard of that name before. As I searched the name of this fellow, it became evident that there were two people bearing the same name who looked completely different! One invented hundreds of uses for peanuts, while the other led some sort of army across America. I stared at the screen, wondering which one my teacher meant. I called my grandfather for a golden piece of advice：flip (掷) a coin. Heads—the commander, and tails—the peanuts guy. Ah! Tails, my report would be about the great man who invented peanut butter, George Washington Carver.
Weeks later, standing before this unfriendly mass, I was totally lost. Oh well, I lowered the paper and sat down at my desk, burning to find out what I had done wrong. As a classmate began his report, it all became clear, “My report is on George Washington, the man who started the American Revolution.” The whole world became quite! How could I know that she meant that George Washington?
Obviously, my grade was awful. Heartbroken but fearless, I decided to turn this around. I talked to Miss Lancelot, but she insisted: No re-dos; no new grade. I felt that the punishment was not justified, and I believed I deserved a second chance. Consequently, I threw myself heartily into my work for the rest of the school year. Ten months later, that chance unfolded as I found myself sitting in the headmaster’s office with my grandfather, now having an entirely different conversation. I smiled and flashed back to the embarrassing moment at the beginning of the year as the headmaster informed me of my option to skip the sixth grade. Justice is sweet!What did the author’s classmates think about his report?
| A．Controversial. | B．Ridiculous. |
| C．Boring. | D．Puzzling. |
Why was the author confused about the task?
| A．He was unfamiliar with American history. |
| B．He followed the advice and flipped a coin. |
| C．He forgot his teacher’s instruction. |
| D．He was new at the school. |
The underlined word “burning” in Para. 3 probably means _______.
| A．annoyed | B．ashamed |
| C．ready | D．eager |
In the end, the author turned things around _______.
| A．by redoing his task |
| B．through his own efforts |
| C．with the help of his grandfather |
| D．under the guidance of his headmaster |
The Basics of Math—Made Clear
Basic Math introduces students to the basic concepts of mathematics, as well as the fundamentals of more tricky areas. These 30 fantastic lectures are designed to provide students with an understanding of arithmetic and to prepare them for Algebra(代数) and beyond.
The lessons in Basic Math cover every basic aspect of arithmetic. They also look into exponents(指数), the order of operations, and square roots. In addition to learning how to perform various mathematical operations, students discover why these operations work, how a particular mathematical topic relates to other branches of mathematics, and how these operations can be used practically.
Basic Math starts from the relatively easier concepts and gradually moves on to the more troublesome ones, so as to allow for steady and sure understanding of the material by students. The lectures offer students the chance to “make sense” of mathematical knowledge that may have seemed so frightening. They also help students prepare for college mathematics and overcome their anxiety about this amazing—and completely understandable—field of study.
By the conclusion of the course, students will have improved their understanding of basic math. They will be able to clear away the mystery(神秘性) of mathematics and face their studies with more confidence than they ever imagined. In addition, they will strengthen their ability to accept new and exciting mathematical challenges.
Professor H. Siegel, honored by Kentucky Educational Television as “the best math teacher in America,” is a devoted teacher and has a gift for explaining mathematical concepts in ways that make them seem clear and obvious. From the basic concrete ideas to the more abstract problems, he is master in making math lectures learner-friendlier and less scary.
With a PhD in Mathematics Education from Georgia State University, Dr. Siegel teaches mathematics at Central Arizona College. His courses include various make-up classes and a number of lectures for future primary school teachers.
If the course fails to provide complete satisfaction to you, you can easily exchange it for any other course that we offer. Or you can get your money back.What does the course Basic Math mainly cover?
| A．Algebra. | B．College Mathematics. |
| C．Arithmetic. | D．Mathematics Education. |
What benefits can students expect from Basic Math?
| A．Stronger imaginative ability. |
| B．Additional presentation skills. |
| C．More mathematical confidence. |
| D．Greater chances of becoming teachers. |
What can we learn about Professor H. Siegel?
| A．He is a guest lecturer at Kentucky Educational Television. |
| B．He is to deliver 30 lectures in Basic Math. |
| C．He works in Georgia State University. |
| D．He specializes in training teachers. |
Where is the passage most likely to have been taken from?
| A．A news report. | B．A book review |
| C．A lesson plan. | D．An advertisement |
阅读下面短文并回答问题
[1]Stamp collectors usually collect stamps only from certain countries or regions. The traditional method of stamp collecting is to organize stamp collection according to the issue dates.
[2]Of course, there are many ____________. You can collect stamps relating to a particular theme. For example, sport lovers may choose the Olympic theme. They try their best to find Olympic stamps issued by various parts of the world every four years. Some of them may want to concentrate on even more specific sport activities like ball games, gymnasium, swimming, etc.
[3]If you like astronomy, you may be keen on collecting stamps describing the stars, planets, spacecraft, spacemen, etc. once you have fixed the topic, you no longer need to bother about stamps other than the theme you selected. Then, you can put all your effort to collect the stamps around it.
[4]China issues zodiac animal stamps (十二生肖邮票) every year to celebrate the Lunar New Year. They are extremely popular and a lot of collectors wait patiently for 12 years to collect a full set of them. Hong Kong’s Lunar New Year special stamp series began in 2000 with the Year of Dragon and the twelfth and final set was issued in 2011, the Year of Rabbit. Recently some Western countries have issued zodiac animal stamps, which attract a lot of attention as well.
[5]You may choose any theme you like. However, you should bear in mind an essential point. The topic you choose should not be too narrow. Otherwise, it is very difficult to accumulate stamps around the topic. You will be depressed and even lose your interest in collecting stamps.
[6]Collecting stamps with themes is especially popular among teenagers because there is a wide range of choices for them. The main challenge is how you organize and expand your collection around your theme.What is the main idea of the passage? （no more than 5 words）
___________________________________________________________________________Fill in the blanks in Paragraph 2 with proper words． （no more than 5 words）
Of course, there are many ____________________________________________.What should you do if you want to collect a full set of zodiac animal stamps? （no more than 7 words）
_______________________________________________________________________________List the three general themes in collecting stamps mentioned in the passage． （3 words）
_______________________________________________________________________________What does the word "them" （Line2, Paragraph6） probably refer to? （1 word）
_______________________________________________________________________________
For those who make journeys across the world, the speed of travel today has turned the countries into a series of villages．Distances between them appear no greater to a modern traveler than those which once faced men as they walked from village to village. Jet planes fly people from one end of the earth to the other, allowing them a freedom of movement undreamt of a hundred years ago.
Yet some people wonder if the revolution in travel has gone too far. A price has been paid, they say, for the conquest (征服) of time and distance. Travel is something to be enjoyed, not endured (忍受). The boat offers leisure and time enough to appreciate the ever-changing sights and sounds of a journey. A journey by train also has a special charm about it. Lakes and forests and wild, open plains sweeping past your carriage window create a grand view in which time and distance mean nothing. On board a plane, however, there is just the blank blue of the sky filling the narrow window of the airplane. The soft lighting, in-flight films and gentle music make up the only world you know, and the hours progress slowly.
Then there is the time spent being "processed" at a modern airport. People are conveyed like robots along walkways; baggage is weighed, tickets produced, examined and produced yet again before the passengers move to another waiting area. Journeys by rail and sea take longer, yes, but the hours devoted to being "processed" at departure and arrival in airports are luckily absent. No wonder, then, that the modern high-speed trains are winning back passengers from the airlines.
Man, however, is now a world traveler and cannot turn his back on the airplane. The working lives of too many people depend upon it; whole new industries have been built around its design and operation. The holiday maker, too, with limited time to spend, patiently endures the busy airports and limited space of the flight to gain those extra hours and even days, relaxing in the sun. speed controls people's lives; time saved, in work or play, is the important thing-or so we are told. Perhaps those first horsemen, riding free across the wild, open plains, were enjoying a better world than the one we know today. They could travel at will, and the clock was not their master.
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What does the writer try to express in Paragraph 1?
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| 2． |
How does the writer support the underlined statement in Paragraph 2?
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| 3． |
According to Paragraph 3, passengers are turning back to modern high-speed trains because．
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| 4． |
What does the last sentence of the passage mean?
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| 5． |
What is the main idea of the passage?
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