A man once said how useless it was to put advertisements in the newspapers．“last week, ”said he, “my umbrella was stolen from a London church．As it was a present, I spent twice its worth in advertising, but didn't get it back．”

    “How did you write your advertisement?” asked one of the listeners, a merchant．

“Here it is,” said the man, taking out of his pocket a slip cut from a newspaper．The other man took it and read, “Lost from the City Church last Sunday evening, a black silk umbrella．The gentleman who finds it will receive ten shillings on leaving it at No.10 Broad Street．”

    “Now, ”Said the merchant, “I often advertise, and find that it pays me well ． But the way in which an advertisement is expressed is of extreme importance．Let us try for your umbrella again, and if it fails, I'll buy you a new one．”

The merchant then took a slip of paper out of his pocket and wrote：“If the man who was seen to take an umbrella from the City Church last Sunday evening doesn't wish to get into trouble, he will return the umbrella to No.10 Broad Street．He is well known．”

    This appeared in the paper, and on the following morning, the man was astonished when he opened the front door．In the doorway lay at least twelve umbrellas of all sizes and colors that had been thrown, and his own was among them．Many of them had notes fastened to them saying that they had been taken by mistake, and begging the loser not to say anything about the matter．

    New York's iconic, blue-green statue of liberty wasn't always green. When the statue was gifted to the US from France in 1885, she was actually a shiny copper color. A new video reveals the chemical reactions involving oxygen and even air pollution that led to her color change from copper to liberty green. The statue of liberty was a gift from France to the US as a way of commemorating the US's fight for independence, as well as their own aspiration for democracy.

    A video, published by the American Chemical Society, explains that the 305-foot (93 meter) statue was built over nine years in sections of copper skin on top of an iron skeleton.

    In her first few decades in the Big Apple, the statue slowly turned from that shiny copper color to a dull brown and the, finally, to the blue-green, or as they'd say back in France, 'verdigris' we see today,' said the video's narrator.

When it changed color, some officials suggested restoring her back to her original color, but after the public protested against this decision, she was left the way she is. The statue's color change was as a result of oxidation reactions between copper and the air. But it was more than one reaction - the color change is due to about 30 years worth of different reactions leading to a mixture of greenish minerals.

    Oxidation reactions happen when an atom loses an electron to another atom.

    In the case of the statue of liberty, her color change was bound to happen due to oxygen in the atmosphere that is 'hungry' for electrons. On top of this, elements of New York City's polluted air added to the color change too.

The first chemical reaction of the color change involved copper giving up electrons to electron-hungry oxygen in the atmosphere. This led to a mineral called cuprite - which is pinkish red.

    Then, cuprite loses even more electrons to oxygen, forming a new mineral（矿物质） called tenorite, which is blackish in color. The black color of tenorite explains why the statue got darker over time, forming a dark brown color.

    Then, further chemical reactions occurred when sulfur（硫） in the atmosphere reacts with oxygen to form sulfur dioxide. Sulfur comes from natural processes such as volcanic eruptions, but also from man-made emissions from boats, cars, airplanes and factories. When sulfur dioxide in the atmosphere reacts with water, it produces sulfuric acid. Sulfuric acid forms green minerals with copper oxides, so the sulfuric acid in the atmosphere made the state green over time.

    Added to that, chloride from the sea spray surrounding Ellis Island where the statue is located made the statue even greener.

    The statue stayed this way for over 100 years because the exposed copper is now oxidized and stable, but the statue wouldn't be the same anywhere else.

    It was Saturday morning. I heard loud noises of moving furniture in the next room. I could almost feel the excitement of John who was soon going to get a room of his own. I remember my own feelings when I was 13. I knew how much he longed for his right to privacy (私人空间) when he was sharing a room with his younger brother, Robot. He said, “Mum, Can I please have a room of my own? I could use Jeff's. He won't mind.”

    It was true that Jeff had graduated from college and flown from the nest. But would he mind? The room was the place where I told him a thousand stories and we had a thousand talks. As close as we were, though, the time came when Jeff needed a door between us. His life was spreading into areas that had less to do with family. I no longer could-or should-know everything about him.

It turned out that getting Jeff's permission was easy. He said, “Of course, Mum, it would be selfish of me to hold on to it.” Then his voice softened, “Mum, I won't be living at home again—you know that.” Behind his glasses, his eyes were lit with all the love. There were no doors closed here—they had all opened up again.

    As John and I were cleaning the room, I fixed my eyes on Jeff's things around me and could almost touch the little boy who I knew was gone forever. I looked at the room and, in my heart, I let it go. To hold on would be, as Jeff said, selfish. Now it was time for John, shouldering through the door, his eyes bright with promise of independence, to disappear behind the door. It was time for letting go to happen again.

    Started by the British Council, the UK's international organization for cultural relations and educational opportunities, this year-long activity sets out to improve fluency in spoken English in particular.

    Prize-winning online competition

    The activity also marked the start of an online competition, “My Favorite English Word”. You can join by simply posting your word of choice on China Daily.com. The most popular words will be included in a draw to win a variety of prizes, including Kindle, Polaroid camera and Bluetooth speaker. To participate, click here.

    English Teacher Award.

    The activity establishes an English Teacher Award to recognize excellence in teaching among Chinese non-native teachers of English. Nominations(提名) will be made by students and English teachers.

    In order to recognize more inspiring teachers, monthly prizes will be presented and the winner of the grand final award will be announced later in the year. The winner will have the opportunity to study in the UK for 4 weeks—supported by the International House London.

    Throughout the activity, the “English is GREAT” website will provide access to free online resources and all kinds of materials for English learners of all levels.

UK-Mandarin (Standard Chinese) Excellence Program

    The “English is GREAT” activity will reply to the UK-Mandarin Excellence Program, started in 2016, which aims to have 5,000 secondary school pupils in the UK fluent in Mandarin by 2020.

    We were on tour a few summers ago, driving through Chicago， when right outside of the city, we got pulled over(被迫停车). A middle-aged policeman came up to the car and was really being troublesome at first. He said,“ You were speeding. Where are you going in such a hurry?” Our guitarist, Tim, told him that we were on our way to Wisconsin to play a show. Then his way towards us totally changed. He asked, “Oh, so you boys are in a band(乐队)?” We told him that we were. He then asked all the usual band questions about the type of music we played and how long we had been at it.

    Suddenly, he stopped and said, “Tim, you want to get out of this ticket, don't you?” Tim said, “Yes.” So the officer asked him to step out of the car. The rest of us, inside the car, didn't know what to think as we watched the policeman talk to Tim. Then the policeman put Tim in the back of the police car and threw the car into reverse(倒车), stopping a few feet in back of our car.

    Now we suddenly felt frightened. We didn't know if we were all going to prison. Suddenly, the policeman's voice came over in a loudspeaker. He said, “Ladies and gentlemen, for the first time ever, we have Tim here singing on Route 90.” Later we knew, the policeman had told Tim that if he sang one of our songs over the loudspeaker in the police car, we would get out of the ticket. Seconds later, Tim started screaming into the receiver. The policeman enjoyed the performance, and sent us on our way without a ticket.

After building some "standard"cargo bikes， {#blank#}1{#/blank#} ，this time with something very special. I wanted to build an ideal cargo bike combining the stability of a three-wheeler with the possibility to change directions like being on two wheels. 
The first step was to do extensive research {#blank#}2{#/blank#} .An incredible source of technical inspiration was the online Tilting Group.Although primarily-concerned with tilting（倾斜） concepts of engine driven constructions，the group is surely the best place to find information about constructing a tilter. 
    After researching and outlining a few ideas，I grabbed some parts and started with a very simple prototype（雏形）.Building such a vehicle needs a high degree of accuracy，which was not the case with my prototype {#blank#}3{#/blank#} .So I made a few more sketches（草图），which led to an improved version of the driving and tilting mechanism. 
    Then I started building the tricycle.Building the structure was quite straightforward.As usual I took an old bike apart for the back triangle and then added the front part.After adding a cargo basket to the structure， {#blank#}4{#/blank#} . 
    Now came the hard part：the driving mechanism.I started with the usual design used for two-wheel cargo bikes，but it took me quite some time to figure out how to pass the driving force to both wheels without allowing the whole thing to lock itself in any angle {#blank#}5{#/blank#} ， but I'm sure I can use the knowledge I gained one way or another. 

A.The project was demanding 
B.I decided to get my hands dirty again 
C.I fell in love with three-wheeler bikes 
D.I put all the parts together for the first time 
E.It took me quite some time to understand the ideas behind it 
F.The engine driven constructions were always the most difficult to fix 
D.The consequence was that the driving mechanism locked itself occasionally