—We can recognize a tree by the shape of its leaves.

—They arrived home while we were having dinner.

—Sorry, I can do nothing to help you in the present.

—I received a letter from my father recently.

—He told him to prepare for the operation.

    More than 450 Chinese people want to live on Mars. They bought one-way tickets to 1 Mars. A club in Netherlands planned to build a city there in 2023. Many people want to inn the2 450 of them are Chinese.

    The club is planning a TV show. 3 can watch how the astronauts(宇航员) live and what they do to get ready for the 4trip.

    "If they get to Mars, they can't come back to Earth. Mars is 5,"its website says. "We should help each astronaut keep 6 and teach them to live and work together to enjoy a 7 future."

    Before leaving Earth, astronauts should practise living and 8 on Mars for eight years. Ma Qiang, a 39-year-old man from Sichuan, China, 9the reporter he hoped to live a new life on Mars. Ma said he survived the 2008 earthquake. He wanted to do10 to make his life different, he told the reporter a trip to Mars could be the answer.

Welcome to "Share Ideas"! I'm Tony Brown. This is Professor Lira He is a scientist. He has many exciting ideas about life in the future. Let's listen to what he has to say!

"I think in the future, travelling will be much cleaner and safer. Most cars will run on solar energy（太阳能). There will be less pollution. The cars will be driven by computers and there will be no accidents(事故). All of the computers will work together with radio signals(信号)."

    "I also think that people will be able to go back to the past through a time tunnel(隧道). If they do something wrong, they will be able to go back and do it again and try not to make the same mistake."

    "Housework will become much easier because you'll just tell a robot to do it."

"In the future, people will be able to talk with each other on the phone more easily, and you'll be able to see the person you're talking to on the screen of the cellphone."

    What do you think life in the future will be like? Send us a letter.

    Our email address: shareideas@yahoo.com.

    See you next time!

    The school of the future will be totally different. The students' desks       (be) digital(电子的), and there will not be human teachers. There will be robots working        teachers. Each student will have a computer instead        carrying many books, and everything will be in the computer.

    In the school of the future, the buildings will have electric stairs. Green energy such as solar energy can be        (use). Technology will lift the school        in the sky. The school buses will be like space ships. In the future, we can learn more at school, not only the knowledge in the books, but also some skills in life.  We can practise       (cook). We can also learn        to drive a car, a plane or a rocket. There will be many educational(教育的)         (programme) on the radio, on TV, or even on the Internet. Many children who live in faraway villages don't need to go to school every day. They can study       (easy) at home.  The food that the school supplies will be much       (healthy). We can get the food from a machine.

              she        at nine o'clock last night?

While he                      the bus, he was         a newspaper.

Their letters                           .

      and        are developing very quickly.

       my grandparents were        , they wrote letters to                             others.