Today there are 6 billion people on the earth. By the year 2050 there may be 12.5 billion. There are a lot of people to feed. We need more food.

One way to produce more food is by growing stronger plants. For thousands of years，farmers have made plants better. Every season, they pick the best plants for the next season. It works very slowly. Since 1983, scientists have been able to change plants more quickly by changing their genetic material (遗传物质). Foods from plants grown in this way are called genetically modified foods (转基因食品), or GM foods.

    By changing the genetic material of a plant, it is possible to make new plants. They make plants which are strong against plant diseases. They can also help with our diseases: a kind of rice is being prepared, for example, which stops people from becoming blind.

    Rich countries produce GM foods because they are easy to grow and bring in more money. Poor countries are interested in them because they help produce more food.

    GM plants are not natural. No one knows how good or bad they are. Making GM foods is only one way of feeding people in 2050. There are strong feelings against them, because they are unnatural. They may feed people, and then hurt them or their children later. But, both rich and poor countries are very interested in their use, and they are not going to go away. In 2050, we may think differently about them.

    Don't be surprised if you see a car going down the road without a driver in Beijing these days.In march, 2018, baidu was given a license to test its self-driving cars in Beijing, China Daily reported.

    Self-driving cars have been in development since 2010, when google announced that it was making such cars. Since then, companies like Tesla, Uber and Baidu have been working to produce and test their own self-driving cars.

    Self-driving cars are expected to change the way we get around. They are safer and more environmentally friendly than regular cars. They can remove the stress(压力) of driving and allow disabled or blind people to get around more easily.

    But self-driving cars have their own disadvantages as well. In one test, researchers pointed a laser pointer（激光棒） at the car's sensors（感应器） while it was moving. The car mistakenly thought that the laser beam（波束） was in its way and slowed down or changed directions.

    The software(软件) that is used to direct the cars may not be safe enough. Reported Live science. Sometimes, without any reasons,it may break down when we use our computers or smartphones. If the software in a self-driving car happened to crash. The results could be deadly.Maybe improvements to the software could solve this problem.

    The sun, the moon and the stars are all in the sky. We see the moon and the stars at night. The sun is a ball. It's much bigger than the moon. It gives us heat (热量). The sun has a family. It's the biggest member of the family. The moon is a ball, too, like the sun and the earth. Sometimes it looks as round as a plate (盘子). Sometimes it looks half a plate. It looks bigger because it's much nearer to the earth. It's much smaller than the sun. It's smaller than the stars. The light (光) on the moon comes from the sun. It has no light of its own.

    The stars look smaller than the sun. They look small because they are very far away from us. All day the stars are in the sky. But the light from the sun is too bright. We can't see the stars in the day.

    Today is December 15, 2030. Influenced by the launch of the first manned mission to Mars next month, you will most likely get a gift card for a space trip.

    The interest in trips, 100km above the surface of the Earth, has grown steadily since such a trip began. However, the market has grown much larger this year since the official announcement of the Mars mission. More low - cost spacelines have entered the market and you can now find flights for such a trip for as low as $3,495.It's very reasonable.

    Space tourism( 旅游业，观光业) is one of the markets that have developed fast during the last decade, with the opening of the Starbright Hotel on the moon as well as the low orbital hotels that started accepting guests. However, accommodation in space is still expensive for the average household, so the suborbital (亚轨道的) flights with thirty - minute weightlessness during the three - hour flight will for some time be the most popular trip.

    However, the spacelines might in the future face fierce competition between space elevators (太空升降舱), like the one that is projected to start construction within two years. Once it is fully functional, it will start to ship cargo to space. But it will accept passengers as soon as possible to get back the large investment. Even if the elevator becomes successful, it will take several years before there are more elevators in the world to get in the competition for space traffic with the spacelines.

    Those who are looking for a little bit of adventure and have extra money to spend may want to consider a suborbital flight in space. While a suborbital flight may not be the space mission that you have always dreamed of, it will give you the rare opportunity to see what our planet looks like in a high - altitude flight outside our atmosl3here. So before you enjoy a trip by elevator to space, enjoy a suborbital flight first.

    Man has a big brain（大脑）. He can think, learn and speak. Scientist once thought that men are different from animals because they could think and learn. They know now that dogs, rats, birds can learn too. They are beginning to understand that men are different from animals because they can speak.

    Animals cannot speak. They make noises when they are afraid, or angry or happy. Apes（类人猿）can understand some things more quickly than men. One or two of them have learnt a few words. But they cannot put words together to make sentences. They cannot think as we do because they have no languages. The language is a wonderful thing. Man is able to build a modern world because he has language.

    Each child can speak his own language very well when he is four or five, but no animal learns to speak. How do children learn it? Scientists don't know. They only know that man can speak because he has the brain.