阅读短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。

    Some of the greatest problems we face today are the destruction (破坏) of our environment． Brown clouds, polluted water, endangered wild animals．．, these problems seem so huge．

    So my family does what we can． We take cloth bags to stores instead of using plastic bags． We walk where we don't have to drive．．．

    But does it do any good? When I am the only one in line at the market with cloth bags, am I doing any good? Does my walking to stores make any real difference to the world?

    I recently learned something about flamingos (火烈鸟) which like to get together in groups of a thousand or more． Every year, when the time comes for migration (迁徙), a few of them first takeoff from the lake． But none of the others seem to notice, so the small group returns．

    However, the next day they try again． This time few more fly along with them, but most of them still pay no attention, so they return again． They try for several times． Every time a few more birds join in but, since the thousands of others still take no notice, the great migration plan is once more stopped．

    Then one day something changes． The same small group of birds once again starts flying and a small number more join in just as before, then more． Finally, they all take flight and the migration really begins．

    What a spectacular sight it must be—thousands of flamingos taking off into the sky at once!

    A few can make a difference． Even if you're the one to take the first step, and continue trying, others will someday take notice and together we will solve even our greatest problems．

    Tom arrived at the New York airport two hours before the flight to Paris. He was wearing three shirts, a jacket, two pairs of socks, a pair of shorts, and two pairs of jeans. He was carrying one small backpack, which was very full, but he didn't have any other luggage. Tom needed to meet a man named Tony before he checked in for his flight. He found Tony near the Air France counter. Tony gave him a round-trip ticket and a small package.

    “Give this package to Jean-Paul at the airport in Paris. He will have a sign with your name on it. I think you can find him easily,” Tony said, ”You don't have any luggage, right?”

    “Only this backpack,” Tom answered. ”You said I could bring one carry-on bag.”

    “That's right. One carry-on bag is fine. Have a good trip.”

    “Thanks.”

    Is Tom a criminal (罪犯)? Not at all. He is an air-courier(空中信使). And he paid only $110 for the round-trip ticket to Paris. Air couriers get cheap airline tickets because they take important packages and papers to foreign countries. Businesses sometimes need to get packages and papers to people in foreign countries by the next day. Often, the only way they can do this is to use an air-courier company. It is not cheap for a business to send a package with an air courier, but it is quick.

    Every year about 80,000 people worldwide travel as air couriers. The number of tickets for courier travel is growing by about 10 percent a year. However, air-courier travel isn't for everyone. But if you have very little money, can be flexible(灵活的) about your travel plans, and don't mind wearing the same clothes for a week, it can be a great way to take a vacation!

    Michael Jackson was one of the world's best singers. He was born in the middle west of the city of Gary， Indiana， in 1958. He began singing with his four brothers. They called the group， “The Jackson Five”. The group became very popular after appearing on a television program. In 1970 the group made their  first record with the name of I Want You Back. It was very popular. One of their hit records was Never Say Goodbye.

    Michael was good at dancing as well as singing， for example， his dance moves and moon walking. He was asked to act in a film in 1978 for the first time， and in the same year he made a record on his own， which was sold eight million copies all over the world.

    Michael nearly didn't go out because he was too famous. Once his fans went off in a faint(晕倒）when they saw him at the concert. No one can do it by now. He lived in a large house and kept lots of animals. He never ate meat. He often raised money for charity. This made him win the Guinness world Records（吉尼斯世界纪录）in 2006. He died on June 25th， 2009， but he would live in our hearts forever.

    O. Henry was a great writer. His pen name was O. Henry and his real name was William Sydney Porter. He was born in North Carolina in 1862. When he was about 20, he went to Texas, where he tried different jobs. He first worked on a newspaper, and then in a bank. When some money went missing from the bank, some people thought he was the thief, so he was sent to prison(监狱). During the three years there, he learned to write short stories. After he got out of the prison, he went to New York and went on writing. He wrote mostly about New York and the life of the poor people there. And people liked his stories very much.