阅读理解

     Most of you know this mathematical game, of course. You and your friend draw crosses and circles on a sheet of paper. You do it one after another. The first pupil who gets three marks in a row wins. But do you know that you can play this game another way and it will become more interesting? You must try to make your friend win. If you get your three marks in a row, you don't win — you lose!

     It is more difficult to play this game the other way. The second pupil can always win (if he plays the right way), but he may not win if the first pupil begins with his mark in the center. Then if the first pupil always takes a place on the other side of his friend's mark, nobody will win.
     If your friend does not know the secret which we have explained, you must play each time so as to leave him the greatest number of ways to win. You may try a few games and you will see how interesting it is to play the game this way.

If you are riding a bike in foreign countries, you need to know what these traffic signs mean.

1		This sign means “walk”, you can cross the street along with other people.
2		This sign is the “don't walk” sign. It means you should stop to wait for a while until the sign of “walk” is showing.
3		This sign means that there is a bike lane. If you see such a sign, you must use the bike lane.
4		Car drivers and bike riders must come to a complete stop at “STOP” signs.
5		This sign means you are coming to a zebra crossing. You must slow down to allow people in the zebra crossing to cross the street.
6		This sign means parts of the road are rough. Be careful! Rough roads make you fall off your bike.

    Many animals do strange things before an earthquake. This news may be important. Earthquakes can kill people and knock down homes. The animals may help to save lives.

Some animals make a lot of noise before an earthquake. Farmers have told about this. Dogs that are usually quiet have started to bark(吠). Horses on farms have run around in circles. Mice have left their holes and run away. Cows have given less milk.

In a town in Italy, cats raced down the street in a group. That happened only a few hours before an earthquake. In San Francisco, a man kept tiny pet frogs. One Sunday, the frogs jumped around more than ever. They made loud noises, like bigger frogs. That night, an earthquake struck the city.

    People want to know when an earthquake is coming. Then they could get away safely. Right now, there is no sure way to know ahead of time. Maybe the best idea is watching the animals.

      The Internet, mobile phones and Ipads are part of our lives now. Technology is greatly affecting all ways of our lives, from the ways we work to the ways we play. And it even causes a number of social problems such as cloning humans.

      We have had lots of technology and it has changed our lives a lot. There is no doubt that humans will continue to use more and more technology. Here are some examples of modern technology that will change our ideas and will affect our lives greatly.

     Global positioning system (GPS) (全球定位系统)

      It's a system that uses radio signals from satellites to show exact information. It tells you where the user is on the earth in all weather conditions. It's made up of three parts: satellites, control equipments(设备) on land and receivers.

     Space Technology

      Russian and American scientists have worked together for the international Space Station (ISS) for a long time. They hope the ISS will provide a long-lasting lab. Such a lab will bring humans limitless (无限的) advantages. It's even hoped that one day space technology will take humans to their new houses in space.

     Underwater Robot

     Hercules is a kind of underwater robot with some high technology equipments. It will be used to look for ancient ships which were destroyed into the deep sea during their journey long ago.

     The world is changing so quickly that it's hard for us to catch up with all the new inventions because they seem to come out every month. It's important for us to learn about new technology and the role that it plays in our lives. So we should be willing to accept modern technology, or we will fall behind the times.

    Australia's Great Barrier Reef(礁) is the world's largest reef system. It is over 2,600 kilometers long. The reef is home to many animals: fish, birds, turtles, sharks and even whales. Unfortunately, the reef that all these animals call home is in danger.

    Climate(气候)change, over fishing and water pollution are damaging(毁坏)the reef every year. Coral(珊瑚)reef experts at Australian universities say that if we do nothing to stop it, the coral reef could be destroyed before the year 2030.

    Everyday things like driving cars, using electricity and running a factory give out greenhouse gases into the air. These gases make Earth warmer and warmer. This is a problem for the Great Barrier Reef and other reefs around the world.

    Coral is very fragile, and even a 2-degree increase in water temperature is enough to kill it, according to Ove Hoegh-Guldberg, reef researcher at the University of Queensland, Australia. If the water temperature doesn't go down, the coral dies.

    But it's not only the coral that's in danger. One quarter of all sea life lives on coral reefs.

    If air pollution is not slowed down or stopped, then the water will warm by at least 3 degrees in the next 20 years, according to reef experts in a report from University of Queensland. This would spell the end for the Great Barrier Reef and all its sea life.

    Science is proving what pet owners have long believed: Dogs understand what we're feeling. Especially, dogs can recognize(识别) the difference between a happy and an angry human face, a study published Thursday in Current Biology suggests.

    It's the first research to show that dogs are sensitive (敏感) to our facial expressions, says the author Ludwig Huber at the University of Veterinary Medicine, Vienna.

    In the Austrian study, 20 different kinds of pet dogs were taught to play a computer game through a series of exercises. In the first step, the dogs were shown two touch screens, one with a circle and one with a square. Through the exercises, they learned that a treat would appear if they chose the right one.

    Eleven of the 20 dogs were able to catch on to rules of the game and make it to the next test, where they were shown photos of happy and angry faces. The dogs were rewarded if they picked certain expression correctly. During the test, the dogs were shown only the upper half or the lower half of a face.

    It was easier to teach the dogs to choose a happy expression than an angry one, suggesting the dogs do indeed understand the meaning behind the expression, Huber says.

    As a test, the dogs were then presented with: the same half of the faces they saw during the training, but from different people， the other half of the faces used in training， the other half of new faces， the left half of the faces used in training.

    In the cases, the dogs chose the right answer 70 to 100 percent of the time.

    Dogs who had been trained to recognize an expression of anger or happiness on the upper part of a face could find the same expression when shown only the lower part. Huber says, "The only possible explanation is that they recall from memory of everyday life how a whole human face looks when happy or angry."

    Dog owners know their pets not only recognize emotions but also understand the feelings.