Stop reading for a minute and think about what you see when you look up at the sky on a clear night. You probably see many stars (星星). Long long ago, farmers watch some stars to know when to plant their crops. Travelers did so to find their way in the dark. Today stars are still important to some people.

    Scientists find that most stars are very big. In fact some stars are so far away that it would take millions of years to get to them even by spaceship.

    Another thing we know today about stars is that some are made up of(由…组成) hot gases. The gases are so hot that they send out light. If you watch a star carefully, you may notice that it twinkles(闪烁)sometimes. As you may understand, light from a star must shine through the air before you can see the star. Air is always moving, it makes light from the star move back and forth. When the light moves, it makes the star twinkle. Stars also have different colors. The colors of a star depend on how hot it is. To our surprise, the cool stars are red and the hottest stars are white.

    In some science fiction movies, evil robots refuse to die, no matter how hard people fight back.

    Now science fiction has become science fact. For the first time, scientists have made a robot that can take a beating (挨打) and keep on going. Scientists from Cornell University made the robot, which looks like a spider with four legs.

    Until now, even the most advanced (先进的) robot was almost certain to break down when it was damaged. That is because its computer inside simply doesn't know how to make the machine work after its shape has changed.

    To deal with this problem, the scientists put eight motors (发动机) and two sensors (传感器) that read how the machine is working. They all give signals to the machine's software. Using this information, the computer can then figure out the machine's shape at any moment.

    The new technology is a big advance in robot-making, scientists say, and it's far from scary. It may someday help scientists create better artificial (假的) arms and legs and give new freedom to people who lose them. It might also help scientists understand how people and animals figure out their own sense of place in space.

    “It has been difficult to design robots that can work well when the environment changes or when it's damaged,” says Olaf Sporns of Indiana University in US. “With this work, we are nearer to solving this problem.”

    If your pen broke at school today, what would you do? You would go to a shop and buy a new one. What if you could simply print out a real, working pen with your 3-D printer without leaving your room?

    Ten years ago people could only see 3-D printing in science fiction movies. But now 3-D printing is here and it's bringing big changes.

    Unlike normal printing that can only copy a 2-D picture with ink. 3-D printing can build almost anything made from material. The printer layers(分层) the material in different shapes to create the object you want to be copied.

    The 3-D printer has been used to make many different things. People have made cups, cars and even an airplane with it. Doctors have been using 3-D printers for several years. People's nervous systems(系统) have been printed out in 3-D form in medical research. Some body parts have been printed and used in hospital. Several months ago, doctors used a 3-D printer to rebuild the face of a person who had a bad accident. In the future, it is expected that the printer will make human organs(器官)to save more lives.

    However there are drawbacks to the printer. At the moment, printing can be quite slow and it's still rather expensive. The average(平均的) price of a household printer is around $1,700, not including the cost of the materials.

    But as the technology develops, it shouldn't be long before disadvantages are improved. Only time will tell where this new technology will take us.

    The biggest influence that technology has on family time is the change of it. People used to spend more time with their family members before. Nowadays, with children (and the parents, too) spending more time texting, watching movies and television, playing video games, and listening to music, when will the family find time to bond (培养感情) and create lasting memories together?

    Far too often we don't pay more attention to making time for members of our own family. By the end of a long day at work or school, members of the family want to relax. And now that technology use is widespread across the country, normally our "relaxing" is also known as spending time on smart phones.

    Not only is the amount of family time affected (影响) by technology, but also the quality. Technology can affect the quality in different ways. For example, family members can be distracted (使分心) by their phones while trying to play a board game together, which wouldn't  have happened if the phone didn't exist in the first place.

    If "family time" means everyone sitting in the same room while playing online, what value is there? Personal interaction is key to time well spent with loved ones. Families don't even need to have something to do while together. If they simply ask each other how their day is and play a simple game together, family bonds will get better.

    When technology becomes a focus, quality(有质量的) time for families goes down, which in turn affects everyone's life. Lack of family interaction causes the family's unity to weaken, and each of the family will be influenced in different ways. Children are more likely to develop unhealthy habits when they fail to interact with their parents. Meanwhile, parents who put work before family or pay less attention to their children's growth are more likely to face bad parent-child relationship. 67 percent of American teens say they want to spend more time with their parents, which is rather sad. Therefore, this passage is meant to show how technology has negatively influenced families.