Imagine this. Somebody hides free books in the subway for you to find and read. Sound exciting? Well, British actress Emma Watson, 26, is doing it! She is known for acting as Hermione Granger in the Harry Potter movies.

    Watson hid 100 copies of a book called Mom & Me & Mom (2013) in London's subway. The book is an autobiography（自传）from US writer Maya Angelou. It tells about the writer's relationship with her mother. These books were put in different places in the subway. People saw Watson doing the same thing in the New York Subway this month.

    With each book, there is a handwritten note by Watson. She asked people to "take special care" of the books if they find them. She also wrote that "when you are finished, please leave it on the subway again for someone else to find".

    Watson's work is part of a movement called Books on the Underground. It calls on people to leave their books on the subway so other people can enjoy them too.

    Hollie Belton, a woman in London, started the movement in 2012. She loves reading on the subway. She noticed that a lot of people shared her habit, so she got the idea. Over the years, Belton has left over 2,000 books of her own. The movement has attracted more and more people.

    Watson is a book lover as well. That's why she tried it. Earlier this year, Watson set up her own online book club Our Shared Shelf. She reads a book every month with others. Mom & Me & Mom is the club's book for November.

    On a Wednesday night, a young man was playing the guitar at the underground station. Some people stopped and put some money into his hat.

    The next day, the young man came to the underground station again. There was a large piece of paper next to his hat. It said，"Last night, a kind man named Chris put something important into my hat. Please come to get it back soon."

    About half an hour later, an old man came and the young man said，"Yes, I knew you would come back."

    "What did you lose？"asked the young man. "$800，000，"answered the old man.

    Then the young man took out a check(支票)and gave it back to the old man. The old man was so happy and thanked the young guitar player.

    Mrs Green sees an ad(广告)in a newspaper for a nice bed in a shop. It costs 100 dollars. Mrs Green likes it, so she goes to the shop. The shopkeeper shows one to her. Mrs Green has a look at it and says, "There aren't any beautiful pillows(枕头)on this bed, but there are many on the bed in your ad. "

    "Yes, madam, that is an ad," answers the shopkeeper. "If you want a bed the same as the one in the ad, you need to pay lo dollars more."

    Mrs Green isn't happy. Then she says, "That's dishonest."

    "Well, madam," answers the shopkeeper. "Look, there is a girl on a bike in an ad in your newspaper too, but can you buy the bike with the girl?"

    We never forget when Perronet came to us. It was on a spring afternoon. We never knew who drowned Perronet, but David pulled him out of the water and saved his life, People sometimes asked us what kind of dog he was, but we never knew, except that he was the nicest possible kind. Mother said we could not afford him because of the tax(税) and his keep. The tax was five shillings(先令), but it was nearly a year before the time when it must be paid. At last, we decided that all three of us would give up sugar toward saving the cost of his keep. It was the hardest for David because he was fond of sweet things, but then, he was fond of Perronet. So we all gave up sugar, and Perronet was allowed to remain.

    We were very happy that summer. The boys were especially happy. The only thing that vexed me was Perronet's tax money, for months and months went on and we didn't save it. One day, I found David alone with Perronet in his arms. He was crying, and feeding Perronet with cake. I can't bear to see boys cry. I begged of David to stop, and told him I should certainly think of something.

    One day, we were all in school. The schoolmaster told us that there was to be a flower show for the school children this year, and that an old gentleman would give prizes to the best arranged wild flowers. There was to be a first prize of five shillings, and a second prize of a half crown, for the best collection of wild flowers, with their names upon them. I squeezed(挤) David's arm, and whispered, "Five shillings!"

    I thought I could never get my lessons that day, for all day I was thinking about Perronet's tax money. At night, I said to them, "Look here! I'll make a collection of flowers. You two can make a collection of mosses(苔藓). There are ten kinds of mosses by the river, and we have names of our own for them." The boys agreed. Richard made me a box. We put wet sand at the bottom, then feather moss, and into that I stuck the flowers. I got all the flowers and all the grasses ready and printed the names on pieces of cardboard, to stick in with them. I didn't like it when it was done, but Richard praised it and that cheered me. I thought their mosses were beautiful.

    The day of the flower show was very hot. When we reached the tent, it was filled with grown-up people. It was very hard work getting about and trying to see the stands with flowers. We kept seeing tickets with "First Prize" and "Second Prize". It made me feel sick with heat and anxiety, to think of them. We had walked slowly all round the tent. We had seen all the cucumbers, onions, lettuce, grapes, long potatoes, round potatoes and everything else. At last we saw my collection! It had a label on it, marked "First Prize", and next to it came the boy's moss, marked "Second Prize". We cried "Perronet is paid for!"