However wealthy we may be, we can never find enough hours in the day to do everything we want. Economics deals with this problem through the concept of opportunity cost, which simply refers to whether someone's time or money could be better spent on something else.
Every hour of our time has a value. For every hour we work at one job we could quite easily be doing another, or be sleeping or watching a film. Each of these options has a different opportunity cost-namely, what they cost us in missed opportunities.
Say you intend to watch a football match but the tickets are expensive and it will take you a couple of hours to get to and from the stadium. Why not, you might reason, watch the game from home and use the leftover money and time to have dinner with friends? This-the alternative use of your cash and time-is the opportunity cost.
For economists, every decision is made by knowledge of what one must forgo-in terms of money and enjoyment-in order to take it up. By knowing precisely what you are receiving and what you are missing out on, you ought to be able to make better-informed, more reasonable decisions. Consider that most famous economic rule of all: there's no such thing as a free lunch. Even if someone offers to take you out to lunch for free, the time you will spend in the restaurant still costs you something in terms of forgone opportunities.
Some people find the idea of opportunity cost extremely discouraging: imagine spending your entire life calculating whether your time would be better spent elsewhere doing something more profitable or enjoyable. Yet, in a sense it's human nature to do precisely that-we assess the advantages and disadvantages of decisions all the time.
In the business world, a popular phrase is "value for money." People want their cash to go as far as possible. However, another is fast obtaining an advantage: "value for time." The biggest restriction on our resources is the number of hours we can devote to something, so we look to maximize the return we get on our investment of time. By reading this passage you are giving over a bit of your time which could be spent doing other activities, such as sleeping and eating. In return, however, this passage will help you to think like an economist, closely considering the opportunity cost of each of your decisions.
According to the passage, the concept of "opportunity cost" is applied to
The "leftover ... time" in Paragraph 3 probably refers to the time
What are forgone opportunities?
Deception (骗术）is something that people do all the time ,and it plays an important role in military (军事的)strategy. Now some researchers are trying to figure out how to get robots to do it, by looking at the behavior of squirrels and birds.
At Georgia Tech, a team led by Ronald Arkin , a professor at the School of interactive Computing, studied the literature on squirrels hiding their acorns (橡果）.Squirrels will hide their food m a certain place, but when they see other squirrels trying to steal from them, they attempt to fool the thieves by running to a fake location.
Ronald Arkin and his Ph. D. student Jaeeun Shim used that as a model for robot behavior. They programmed the robot into tricking a “predator (捕食者）” machine by doing what εi squirrel does： showing the enemy a false location for an important resource.
The team also looked at how other animals in this case，a species of bird called Arabian babbler~ drive off predators. A babbler will make an alarm call when they see a predator and other babblers will join the bird and make more calls. They then surround the predator, all the while flapping (拍打）wings and making noises. The babblers don’t ever actually fight the animal they want to drive off； they just make enough noises and flaps around enough so that it seems that attacking a babbler isn’t worth it
They found that the deception works when the group reaches a certain size—essentially, when enough birds arrive to convince the enemy that it’s best to back off . Davis modeled that behavior in software using a military scene and found that it worked even if the group didn’t have the firepower to confront the enemy directly.
The military is interested in this because a robot that can fool an opponent is a valuable tool. It could lead an enemy down a fake trail or make itself look more dangerous than it actually is.Why does the military want to take advantage of squirrels’trick?
| A．It can reduce the use of firepower to confront the enemy. |
| B．It can fool the enemy into believing it is more dangerous. |
| C．It can lead the enemy in a wrong direction to avoid losing resources. |
| D．It can scare the enemy away who wants to destroy the acorns. |
Which of the following is NOT the way Arabian babblers drive off predators?
| A．One bird makes an alarm call and other birds will join it |
| B．They fight the enemy bravely face to face. |
| C．They make noises and flaps around the predator. |
| D．They force the predator aware that it isn't worthwhile to attack. |
What is the main idea of the passage?
| A．Animals' behaviors are researched to be applied to the study of military robots. |
| B．Robots, fooling tricks are applied to the study of animals’behaviors. |
| C．Birds and squirrels are the animals that are good at deception. |
| D．Researchers are interested m animals’military-related behaviors. |
UGG boots have been a winter-weather fashion for several years now, combining function, comfort, warmth and even some style. What many UGG-enthusiasts don’t know is that their boots are a breeding ground for bacteria and cause foot problems.
Doctors believe the boots, which are particularly popular among young teenage girls, are leading to a rise in the number of people suffering pains in their feet and knees.
Dr. Ian Drysdale，head of the British College of Osteopathic Medicine，believes because the foot does not get the proper support on the inside，it will lead to more ankle，knee，hip and back problems. “These boots are not designed for outside wear. Just because something becomes a trend or fashionable doesn’t mean it’s good or right，” he said, “The particular problem with this type of footwear is that it is unsupported. It’s a slipper. You wouldn’t normally expect to be doing outdoor activities from something that’s indoor. If you decide to wear your pajamas outside all. the time, someone will come up and say it’s not a good idea. ” Dr. Drysdale explained that the feet issues become a particular problem among young teenage girls，whose bones are “ plastic ” and developing when they are growing. “ If that structure is developing in an inappropriate way,” he said, “then the ultimate structure will be deformed ”
Mike 0，NeiU, a consultant surgeon, said, “As the foot slides around, you get wear and tear (磨损）on the joints on the inside of the foot The ankle is m the wrong position, the thigh bone also changes position, and you get an abnormal movement in the pelvis, which leads to back problems. ”
UGG AustraUa9 who makes the designer version of the boots, told The Daily Mirror that their boots are “comfort” rather than “performance” footwear and consumers should be aware of “knockoffs”（仿制品)which lack reinforced heels in their boots.Teenage girls prefer to wear UGG boots because of the following except______
| A．design | B．comfort | C．quality | D．warmth |
Accordi^ to Dr. Ian Drysdale，_____
| A．there is a possibility that bacteria will multiply in UGG boots |
| B．wearing UGG boots will lead to more ankle and toe problems |
| C．it’s not a good idea to wear boots like UGG outside all the time |
| D．teenage girl’s bones are plastic enough to wear UGG boots |
The underlined word “ deformed” is closest in meaning to_____
A. shaped B_ strengthened C. reformed D. damagedWhich of the following can be the best title for the text?
| A．Potential Harm of UGG Boots | B．The Popularity of UGG Boots |
| C．The Unique Design of UGG Boots | D．Benefits of UGG Boots |
Oyster
What is an Oyster card?
Oyster is the easiest way to pay for journeys on the bus ，Tube ，tram，Docklands light Railway (DLR)，London Overground and National Rail journeys in London You can store your travel cards, Bus & Tram Pass，season tickets and credit to pay for journeys as you go.
Where to get an Oyster card?
There are a number of ways for you to get an Oyster card ：
•At over 3,900 Oyster Ticket stops
•At Tube and London Overground station ticket offices
•At some National Rail stations
•At London Travel information Centres
•Online at tfl. gov. uk/oyster
How to use an Oyster card?
To pay the correct fare on the Tube ，DLR，London Overground and National Rail services，you must always touch m on the yellow Oyster card reader at the start of your journey，and touch out at the end. ff you don’t, a maximum cash Oyster fare will be changed When using the bus or tram, you must only touch in at the start, but not at the end of your journey.
What happens if I don’t visit London very often?
Don’t worry. Any pay as you go credit on your card will not expire (过期)，so you can keep it for your next visit or lend it to a friend.
Fares
Traveling by Tube from Central London (Zone l)to Heathrow (Zone 6)
Adult Oyster single fare
£ 4. 20 Monday to Friday 06:30 - 09:30 and 16:00 一 19:00
£ 2. 70 at all other times including public holidays
Adult single cash fare £ 5.00
For further information，visit tfL.gov. uk /fares.You can get an Oyster card at the following plaices EXCEPT_____
| A．on the website | B．at an Oyster Ticket stop |
| C．at a post office | D．at a Tube station |
Which of the following is TRUE about Oyster cards?
| A．They are limited in use to the owners themselves. |
| B．On National Rail services you must touch them on the reader twice. |
| C．They are not suitable for those who don’t visit London often. |
| D．Oyster card Tube fares cost more on public holidays than on weekdays. |
H a person with an Oyster card fakes the 7 o’clock Tube from Central London to Heathrow for a week (no public holiday in between)，he should pay_____.
| A．f 18.90 | B．£ 29.40 | C．£21.90 | D．f26.40 |
The passage is probably taken from a_______
A journal B. travel brochure C. textbook D. novel
Years ago a farmer owned land along the Atlantic. He constantly advertised for hired hands. Most people were not willing to work on farms along the Atlantic because they worried about the terrible storms that destroy buildings and crops. The farmer received a steady stream of refusals at the interview for a farmhand
Finally, a short, thin man approached the farmer. “Are you a good farmhand?” the farmer asked him.
“Well, I can sleep when the wind blows. ” answered the little man.
Although puzzled by this answer ，the farmer, desperate for help, hired him. The little man worked well around the farm ，busy from dawn to dusk, and the farmer felt satisfied with the man's work.
Then one night the wind howled loudly from offshore. Jumping out of bed，the farmer grabbed a lantern and rushed next door to the hired hand’s sleeping quarters. He shook the little man and yelled， “ Get up! A storm is coming! Tie things down before they are blown away! ”
The little man rolled over in bed and said firmly, “No sir. I told you, I can sleep when the wind blows. ”
Enraged (激怒）by the response, the farmer was tempted to fire him on the spot ,Instead, he hurried outside to prepare for the storm. To his amazement，he discovered that all of the hay had been covered. The cows were in the bam，the chickens were in the coops，and the doors were barred The shutters were tightly secured. Everything was tied down, Nothing could be blown away.
The farmer then understood what his hired hand meant, so he also returned to his bed to sleep while the wind was still blowing.Why did the farmer constantly advertise for hired hands?
| A．Because he needed hired hands all. the year round. |
| B．Because there was too much work to do on the farm. |
| C．Because he could hardly hire a farmhand. |
| D．Because he offered poor conditions for the hired hands. |
The farmer felt amazed because _______
| A．the Little man was sleeping | B．everything was in safety |
| C．the wind was too strong | D．he could not open the doors |
What did the man mean by saying “I can sleep when the wind blows. ” ?
| A．He needed much sleep after working hard on the farm. |
| B．He was very brave and not afraid of wind |
| C．He enjoyed sleeping when the wind blew. |
| D．He would get everything done before the wind blew. |
Which of the following statements about the Little man is TRUE?
| A．He was not afraid of storms. |
| B．He was a heavy sleeper under any condition |
| C．He was hard-working and devoted to his work. |
| D．He was fired shortly after he tied everything down. |
[1]All people have dreams and they obey the rule that if you can dream it, you can achieve it! Here are four goals for people to reach a perfect life in their future.
[2]The first goal common to all of us in health and energy. We all want to be healthy and fit, to have high levels of energy and to live free of pain and illness. Today, with the incredible advances in medical science, the quality of our health and fitness, and our lifespan, is largely determined by design, not by chance. People with excellent health habits are far healthier, have more energy, and live longer and better than people who have poor health habits. Remember that health is not everything, but without health everything is nothing!
[3]The second goal that we all have in common is to enjoy excellent relationships – intimate, personal or social – with the people we like and respect, and who is turn. Fully 85% of your happiness will be determined by the quality of your relationships at each stage, and in each area, of your life. How well you get along with people, and how much they , have more impact on the quality of your life than perhaps any other factor.
The third common goal is to do work that we enjoy, to do it well, and to be well paid for it. You want to be able to get and keep the job you want, to get paid more and promoted faster. You want to earn the very most that is possible for you at each stage of your career, whatever you do.
The fourth goal we all have in common is to achieve financial independence. You want to reach the point in life where you have enough money so that you never have any financial worries. You want to be completely free of them. You want to be able to order dinner in a restaurant without referring to the price listing to determine what you want to eat.What does this passage chiefly talk about? (no more than 12 words)
Fill in the blank in Paragraph 3 with proper words. (no more than 6 words), and who is turn
Complete the following sentence with proper words according to Paragraph 4? (no more than 6 words)
Everybody wants to make no matter what job he is engaged in.Why does the author put health ahead of other goals? (no more than 20 words)
What does the underlined word “them” in the last paragraph probably refer to? (no more than 3 words)