Best friends may be priceless but the cost of keeping the relationship alive is £23,870.

    According to a study, a BFF (best friends forever) does not come cheap with devoted friends spending £4,679 on birthday presents alone over a lifetime. And while it costs nothing to be a shoulder to cry on, big-hearted Britons go the extra mile and spend £168 on pick-me-ups(提神物品) to get their mate through a rocky patch (艰难时刻)like the breakup of a relationship.

    There's a further £242 spent on presents to show how much they mean from gifts bought on holiday to treats for no reason. And distance does not break up a close friendship as BFFs spend a whopping(巨大的) £18,000 on travel to see each other despite being miles apart because of university, jobs and marriage.

    The study by cashback site TopCashBack found on average BEFs who marry can expect £431 spent on them and a further £283 on gifts when they have children. And they can rely on their pals to help out when they move houses as they will obtain £127 worth of housewarming presents and takeaways(a kind of food).

    The survey based on a friendship lasting 40 years found more than eight in ten adults with a BFF felt their friendships were worth every penny.

    TopCashback spokesperson Natasha Smith said: “Those friendships which stand the test of time are often the most important in our lives. However, they come at a cost. From train tickets once a month to flights and a new dress for a wedding on the Italian coast, the price paid for having a best mate can soon add up. But when we asked people to compare their friendship with the financial investment(投资), only 14% thought their friendship was equal to their investment with the vast majority thinking it was worth more."

    Going green seems to be fad(时尚)for a lot of people these days.Whether that is good or bad，we can't really say, but for the two of us，going green is not a fad but a lifestyle．

    On April22nd，2011，We decided to go green every single day for an entire year．This meant doing 365 different green things，and it also meant challenging ourselves to go green beyond easy things．Rather than recycle and reduce our energy, we had to think of 365 different green  things to do and this was no easy task．

    With the idea of going green every single day for a year .Our Green Year started．My wife and I decided to educate people about how they could go green in their lives and hoped we could show people all the green things that could be done to help the environment．We wanted to push the message that every little bit helps．

    Over the course of our Green Year, we completely changed our lifestyle．We now shop at organic(有机的) stores．We consume less meat, choosing green food．We have greatly reduced our buying we don't need．We have away half of what we owned through websites．Our home is kept clean by vinegar and lemon juice, with no chemical cleaners. We make our own butter, enjoying the smell of home-made flesh bread .In our home office anyone caught doing something ungreen might be punished．

    Our minds have been changed by Our Green Year．We are grateful for the chance to have been able to go green and educate others .We believe that we do have the power to change things and help our planet．

    The year 3700, Earth is far too hot for any human to call it home. On this planet at least, man is nothing more than a memory--if there is anything left to remember the "wise man". But what about our wisdom--will any of it survive us?

    The conventional answer is no. Knowledge requires a knower, and there will be no knowing minds around then. But if information survives, perhaps in books or hard drives, maybe the knowledge isn't quite dead but dormant(休眠), ready to become alive with the help of other minds that develop over time or come to visit Earth in the distant future.

    At first sight, that seems to be reasonable: after all, we have done similar things with past knowledge. For example, we saved an ancient computer from a ship destroyed at sea off the southern coast of Greece, and succeeded in finding the meaning of Egyptian hieroglyphics(象形文字). Careful work can bring previously lost wisdom back to life.

    However, the key point is that there is a certain cultural continuity with those ancient times that allows us to reason and make progress in the dark: we know we are dealing with the legacy(遗产)of other humans. Without that link, the survival of objects and raw data doesn't guarantee the survival of knowledge. And a lack of continuity in language with any future intelligence would be a barrier. Knowledge is closely connected with language. When a language dies out, we can lose systems of reasoning that they contain. If that's lost, then it can't be recovered.

    All this means that other minds might not be able to fully make human knowledge alive when we are gone. It is better to concentrate on not dying out in the first place.

    Have you ever been afraid to talk back when you were treated unfairly? Have you ever bought something just because the salesman talked you into it? Many people are afraid to speak out for their rights. Dr Robert Albert, author of Stand Up, Speak Out, and Talk Back thinks it's because their self-respect is low.

    But Albert and other scientists are doing something to help people help themselves. They offer "assertiveness training" courses A. T. for short. In the A.T. Course people learn that they have a right to be themselves. They learn to speak out and feel good about doing so. They learn to help themselves without hurting other people.

In one way, learning to speak out is to get rid of fear. A group taking an A. T. Course will help the shy person to lose his fear. But A. T.uses an even stronger motive— he needs to share. The shy person speaks out in the group because he wants to tell how he feels. Whether or not you speak up for yourself depends on your self-respect. If someone you face is more "important" than you, you may feel less of a person. You start to doubt your answers to problems. You can get to feel good about yourself. And once you do you can learn to speak out.

    A mother goat is able to pick out her own baby from its voice alone by the time the kid is just five days old.

    Researchers from University of London played kids' bleats to female goats and studied their responses. They were surprised to find that the animals were able to pick out their own kids' voices.

    “A mother and the kid rely a lot on smell to recognize one another and, in the wild, during the first week of their lives, the animals hide in grass and don't call much. It's a strategy they use to avoid enemies,” Dr Elodie Briefer, who led the research, explained to BBC News. “The mother call to the kids when she want them to come and feed, so we expected that kids would recognize the mothers' voices.” In fact, this was the case for deer, which also use this hiding strategy, although they do not belong to the same family of species as goats.

    She and her team recorded and played back young kids' calls to the female goats and recorded their responses. She explained, “Even when the calls came from kids that are five to six days old, we could see the mothers responding more to the voices of their own babies.” Hearing the voice of their own kids, the females would look towards the speaker that the sound was coming from, moving around and calling in response.

    The scientists say that understanding how goats behave and communicate is very important. “This helps us understand just how smart these animals are,” said Dr. Briefer. “Farmers might be able to change their way to raise goats considering this natural behaviour.”

    If you're a cycling lover, you will have to pay a lot of attention to your bicycle and maintain it well, for bicycle parts are exposed to wear and tear (磨损) over time and you have to examine the bicycle to see if there are any signs of wearing such as scratches, dents (凹陷) etc. Sometimes, a part may not work because it has exceeded its life expectancy. Sometimes, you will need to find replacement parts for it to keep up the performance of the bicycle.

    Different parts of a bicycle will wear at different rates so it is very important that you have a basic understanding about the role played by each part. One of the most important parts of the bicycle is the frame. You will need to choose a frame that lasts for a very long time. Of course, you will see some paint scratches after some time. When you're selecting a frame, you have to think about the material. Aluminium (铝) frames will not rust easily, but they have a higher chance to dent. Steel frames will be hard to dent, but you will need to make sure they get a good paint job so that they won't rust.

    Wheels also experience a lot of wear and tear and you should go for a professional seller when you want to buy wheels. There are different types of wheels that you can buy, like Zipp wheels that provide more aerodynamic efficiency (空气动力学效能). Investing in new tyres instead of going for used is a good idea because you will be able to get more use out of it. The same goes for chain as there's a higher chance of a used chain breaking. You may also experience shifting problems. However, some parts of bicycles such as pedals can be used for a long time and you can find different styles.

    Other parts that you can buy used are seats, handlebars and the stem. When you are buying handlebars, you have to see if there are any dents or if they have been bent out of shape. There shouldn't be any cracks in the seat post or the handlebars. There are many shops where you can buy parts, so you will have to check the references to see how customers respond to them before you buy anything.