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 readmg 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 .
| A．making more money | B．taking more opportunities |
| C．reducing missed opportunities | D．weighing the choice of opportunities |
Hie "leftover ... time" in Paragraph 3 probably refers to the time .
| A．spared for watching the match at home |
| B．taken to have dinner with friends |
| C．spent on the way to and from the match |
| D．saved from not going to watch the match |
What are forgone opportunities?
| A．Opportunities you forget in decision-making. |
| B．Opportunities you give up for better ones. |
| C．Opportunities you miss accidentally. |
| D．Opportunities you make up for. |
I woke up late and had breakfast in a hurry. I had never been late and didn’t want my boss to be unsatisfied.
However, it seemed that day wasn’t a lucky one for me from the very second I left my flat. The moment I wanted to rush downstairs one of my stiletto heels(细高跟) broke. I had to return to change my red shoes. I also had to change my purse and other little things that I had tried to match the red shoes. I was sure I would be late for work.
On my way to work I had to wait for over half an hour because of an accident. I had no choice but to wait. I phoned my boss and he told me that it was no problem, but he needed me for the meeting with the Japanese clients(客户) that morning.
Finally, I arrived at the office one hour later. I had to keep calm and be fresh for the meeting to make the clients sure that our plan was the best for their future commercial(商业的) project. However, when I was going to present(介绍) it to the clients, I found that I left the plan I had made the night before at home. I was about to get angry when I realized that I had a draft(草稿) of it in my office.
At last, the presentation came to an end and it proved to be a success. But I had to say that I had a terrible day, full of incidents.Which of the following is NOT the reason for the writer’s being late for her work?
| A．She got up late in the morning. |
| B．She changed her purse and other little things. |
| C．One of her shoe heels broke. |
| D．She had to wait for her friend for half an hour.. |
According to the passage, what could we learn about the writer?
| A．Her boss was very angry with her. |
| B．She often arrived at her office on time. |
| C．She left her plan on the bus. |
| D．She was nervous at the meeting. |
What did the clients think of the writer’s presentation?
| A．Dull. | B．Just so-so. | C．Excellent. | D．Terrible. |
With only about 1,000 pandas left in the world, China is desperately trying to clone (克隆) the animal and save the endangered species(物种). That’s a move similar to what a Texas A&M University researchers have been undertaking for the past five years in a project called “Noah’s Ark”.
Noah’s Ark is aimed at collecting eggs, embryos(胚胎)，semen and DNA of endangered animals and storing them in liquid nitrogen（氮）. If certain species should become extinct , Dr. Duane Kraemar, a professor in Texas A&M University Medicine, says there would be enough of the basic building blocks to reintroduce the species in the future.
It is estimated that as many as 2,000 species of mammals , birds reptiles will become extinct in over 100 years . The panda, native only to China , is in danger of becoming extinct in the next 25 years .
This week , Chinese scientists said they grew an embryo by introducing cells from a dead female panda into the egg cells of a Japanese white rabbit . They are now trying to implant the embryo into a host animal.
The entire procedure could take from three to five years to complete.
“The nuclear transfer(核子移植) of one species to another is not easy, and the lack of available(capable of being used) panda eggs could be a major problem，” Kraemer believes. “They will probably have to do several hundred transfers to result in one pregnancy(having a baby). It takes a long time and it’s difficult, but this could be groundbreaking science if it works. They are certainly not putting any live pandas at risk, so it is worth the effort, ”adds Kraemer, who is one of the leaders of the Project at Texas A & M, the first–ever attempt at cloning a dog.
“They are trying to do something that’s never been done, and this is very similar to our work in Noah’s Ark. We’re both trying to save animals that face extinction. I certainly appreciate their effort and there’s a lot we can learn from what they are attempting to do. It’s a research that is very much needed.” The aim of “Noah’s Ark” project is to ________.
| A．make efforts to clone the endangered pandas |
| B．save endangered animals from dying out |
| C．collect DNA of endangered animals to study |
| D．transfer the nuclear of one animal to another |
Ａccording to Professor Kraemer , the major problem in cloning pandas would be the lack of _______.
| A．available panda eggs | B．host animals |
| C．qualified researchers | D．enough money |
The best title for the passage may be ______.
| A．China’s Success in Panda Cloning |
| B．The First Cloned Panda in the World |
| C．Exploring the Possibility to Clone Pandas |
| D．China---the Native Place of Pandas Forever |
Are you looking for something different this summer? We’ve lined up a list of some unusual camps.
Learn to fly a jet(喷气式飞机)
This is the real training that all fighter and test pilots have . Learn the cockpit(驾驶室) and how to put your plane through its paces . Finally, you fight a mock battle with your teammates.
It’s held at the U.S . Space &Rocket Center in Huntsville, Alaska. There are both weekend and summer camps for anyone 9 and up. Kids 7 to 12 also can pair with a parent. The cost is $749 for kids-only camps and $349 each for parent /child camp.
Be Steven Spielberg
At Film Camp, you will get to write, direct, shoot and edit your own movie.
Run by the New York Film Academy, you can choose from a variety of camp locations: New York, Disney-MGM Studios in Florida, Universal Studios in Los Angeles, Harvard University, Paris or Florence, Italy.
Everyone helps one another by working behind the camera. Tuition for a one—week camp is$1,500, while a four or six week training run $5,900 to $6,900.
Join the circus
At Circus Smirkus you can learn how to ride a unicycle, and throw a pie in someone’s face .
Kids 8 to 16 can choose between one—or two-week sessions, with the two-week camp ending in a circus show for the families.
The camp is located in Craftsbury Common, Vermont. The cost is $825 for one week ($300 extra with a parent ) and $1,500 for two weeks ( $ 500 extra with a parent).
Live the ultimate (终极的)summer fantasy
Learn to ride the waves this summer and tour one of the world’s only sea turtle hospitals at Surf Camp. The week long camp also includes trips to local islands.
Surf Camp is located at Wrightsville Beach, North Carolina. The cost is $475 per week for kids 8 to 12, $595 per week for teens 12 to 18. Check it out at wbsurfcamp. Com.
Strike a chord(弦)
At Power Chord Academy, teens 12 to 18 will be placed in a band that best meets their age, experience and style. You will lead the life of a band member: recording in a studio, playing a concert and making a video.Which camps can you join if you want your father to be able to take part?
| A．The camp at the U．S Space &Rocket Center and Circus Smirkus |
| B．The Power Chord Academy and Film Camp |
| C．The camp at the U.S Space & Rocked Center and Film Camp |
| D．Circus Smirkus and Surf Camp |
How much do you have to pay if you want to attend a 2- week circus camp with your mom?
| A．$ 2250 | B．$ 1500 | C．$ 3000 | D．$ 2000 |
Surf Camp can provide the following for campers EXCEPT______.
| A．surfing | B．care for sea turtles |
| C．meeting with lovers of surfing | D．travel to local islands |
What does the underlined word “mock” mean ?
| A．real | B．fierce | C．shooting | D．pretended |
Find which Direction Is South
Do you have a good sense of direction？If not，please take with you a compass. But if you forget to take a compass , you can still find your way.
It's never a good 
idea to imagine that the family member who was entrusted(委托〕with the job of map reading actually knows where the family is. You can tell by the "slightly confused look on their face that nothing on the ground seems to match the map. Never mind. The sun is shining and it’s still morning. If you don't know the exact time，you can still find out where south is，but you'll need to be patient.
①Find a straight stick and put it in the ground in a place where you can mark its shadow.
②Try to position the stick as vertically(垂直)as you can. You can check this by making a simple plumb line（铅锤线）with a piece of string（绳子） and weigh. You haven't got any string? Ok, use a thread from your clothes with a button tied at the end to act as a weight.
③Mark the end of the shadow cast by the stick.
④Wait approximately half an hour and mark the end of the shadow again.
⑤Keep doing this until you have made several marks.
⑥The mark nearest the stick will represent the shortest shadow, which is cast at midday, when the sun is highest in the sky and pointing to the exact south.
⑦Pick a point in the distance along the line between the shortest shadow and the stick.
⑧That point is south of where you are.
⑨Now you can turn the map, like you did before, and find which way you should be traveling.To find the direction, we ought to be patient probably because ________.
| A．it is not easy to find a proper stick |
| B．it is not easy to position the stick |
| C．it takes hours to make the marks |
| D．it takes about half an hour to make the marks |
The passage would probably be most helpful to ________.
| A．those who draw maps |
| B．those who get lost |
| C．those who make compasses |
| D．those who do experiments |
Which of the following pictures best shows the way of finding the direction of south?
The author presents this passage by ________.
| A．telling an interesting story |
| B．describing an activity in a lively way |
| C．testing an idea by reasoning |
| D．introducing a practical method |
It`s not easy being a teenager (13—19岁的青少年)----- nor is it easy being the parent of a teenager. You can make your child feel angry , hurt, or misunderstood by what you say without realizing it yourself . It is important to give your child the space he needs to grow while gently letting him know that you’ll still be there for him when he needs you.
Expect a lot from your child ,just not everything . Expect for health and safety problems , such as drug use or careless driving, consider everything else open to discussion . If your child is unwilling to discuss something , don’t insist he tell you what’s on his mind . The more you insist , the more likely that he 'll clam up . Instead, let him attempt to solve（解决）things by himself. At the same time, remind him that you’re always there for him should he seek advice or help. Show respect for your teenager’s privacy(隐私).Never read his mail or listen in on personal conversations.
Teach your teenager that the family phone is for the whole family . If your child talks on the family’s telephone for too long., tell him he can talk for 15 minutes ,but then he must stay off the phone for at least an equal period of time. This not only frees up the line so that other family members can make and receive calls , but teaches your teenager moderation(节制) .Or if you are open to the idea, allow your teenager his own phone that he pays for with his own pocket money or a part—time job.The main purpose of the text is to tell parents ________.
| A．how to get along with a teenager |
| B．how to respect a teenager |
| C．how to understand a teenager |
| D．how to help a teenager grow up |
What does the phrase “clam up ” in Paragraph 2 probably mean?
A. become excited Ｂ．show respect C. refuse to talk D. seek helpThe last paragraph is about how to teach a teenager __________.
| A．to use the phone in a sensible way |
| B．to pay for his own telephone |
| C．to share the phone with friends |
| D．to answer the phone quickly |
What should parents do in raising a teenager according to the text?
| A．Not allow him to learn driving or take drugs. |
| B．Give him advice only when necessary |
| C．Let him have his own telephone |
| D．Not talk about personal things with him |