Hands play an important part in our daily life. But do you know which of your two hands you use more? Very few people use both hands equally well. Most of us are right-handed. Only about five people out of a hundred are left-handed. New-born babies can take hold of things with either of their hands, but in about two years they usually use their right hands. Scientists don't know why this happens.

Monkeys are our close relatives in the animal world. Scientists have found that monkeys like to use one of their hands more than the other, but it can be either hand. There are as many right-handed monkeys as left-handed ones. Next time you visit a zoo, watch the monkeys carefully, you will see that some of them will use their right hands and others will use their left hands. But most of the people use their right hands better and this makes life difficult for those left-handed people. We live in a right-handed world.

    We see many animals, like rabbits, bees, dogs, birds, sheep…，but do you know 1these animals say things? First，let's see a rabbit. When a rabbit sees 2dangerous(危险的)，it runs away at once. When it runs, its tail moves up and 3.When others see this, they run away,4.

    Many other animals use this kind of language(语言). When a bee has found some food, it goes back to 5home. It cannot tell6bees where the food is by speaking to them，but it does a little dance in the air. This may tell other bees 7the food is.

    Some animals say things by8sounds like a man does. For example，a dog barks when a stranger(陌生人)comes near. Some birds can make several 9sounds, each with its own meaning. In a word, every animal10its own language.

    A major development to self-driving cars may change the way we will drive in the future. Google, the leading company in self-driving technology, has changed its develop plan. It had driverless cars built by car factories, but now it will start building its own cars.

    Google has started to build some kinds of experimental electric self- driving cars that look like a Smart car or Fiat 500. There is no steering wheel(方向盘), gas pedal or brake. The only things a human passenger controls are a red "e-stop" button (按钮) for fear stops and a start button. The car's only "friendly" face is designed to make it help people accept self-driving technology.

Google workers took part in a long experiment, in which they used self-driving cars for their usual travel to work. No accident happened, but Google's heads realized that depending on a human passenger to drive in an emergency(紧急情况) wouldn't work because they may be reading, working , or sleeping. Now the self-driving car drives by itself if the driver takes his hands off the wheel for over ten seconds.

Google recently announced that its cars had covered 700,000 miles of public roads, and they were now running in busy city streets. People who love self-driving cars say this will improve transport by making roads safer, cutting down accident, and making less pollution.

    Of course, there's no need to look for parking at a crowded shopping mall. Instead, users could let their self-driving cars drop them off to park itself. A mother who took a test ride said that having the car would allow her more time to catch up with her son. The cars could also allow people who might not be able to drive to enjoy the hand-free driving. And drunk driving? Not a problem. It is very likely that by 2020, driverless cars will be common. Do you believe so?

    Do you often drink bottled drinks? Of course 1  is so cool to get a cold one right out of the fridge, right? But all those plastic bottles use a lot of oil and  2 the environment. Americans buy 3 bottled water than any other nation in the world. In order to make all these bottles, 17 million barrels (桶) of oil  4up. That's enough oil to keep a million cars going for twelve months.

    Many people choose 5 the bottles away after having the bottled drinks. In fact, instead of going out with the trash, plastic bottles can be turned into carpeting for clothing. Remember this: Recycling one plastic bottle  6save enough energy to power a 60-watt light bulb for six hours.7 , for every six water bottles we use, only one is recycled. The rest are sent as garbage (垃圾). Or, even worse, they end up 8  trash on the land or in rivers and oceans.

    So why don't more people drink water from the kitchen? Some people drink bottled water 9 they think it is better for them, but that's not true. The chemicals in the bottles themselves may get into the water which can do harm to people.

    So next time when you have drinks or water, please  10 to use a glass at home or carry water in a steel bottle. And if you want to do something more, try to collect plastic bottles and send them for recycling.

    Each one of us shares this planet with seven billion others. And we all need 1. People and products need to move from city to city and country to country. However, we all know 2 most cars, motorcycles, boats and planes cause air pollution. They are also 3.This is a serious problem in many cities.4 inventors are coming up with creative ideas to try to reduce the pollution and noise.

    In many cities around the world, motorcycles are very 5. Now Vietnam has around 33 million motorcycles and China has almost 120 million. Motorcycles are a faster and cheaper way to get around a city than 6. Yet air pollution is a growing problem. In large cities, people7it is difficult to breathe. To solve these problems, a US company designed an environmentally friendly motorcycle. It uses electricity as fuel (燃料). As a result, there is 8 pollution. It's also quiet and fast. This makes 9 a good choice for getting around a city.

    The Italian city of Venice is a city with only a few 10. There are no cars in the city center,11 cars, water taxis and buses carry people along the city's canals (运河). However, they cause pollution, 12 to the water. English engineers Dick and Jim designed a solar –powered(太阳能) water taxi. The water taxi 13 run for a day after being recharged(重新充电). Planes also cause air and noise pollution. Designing an environmentally friendly airplane is a real 14. Some airplane companies have 15 to solve the problems. Swiss engineers have gone one step further. They developed a solar airplane. This plane holds the world record for the longest solar-powered flight-1,541 kilometers from Arizona to Texas in America.

    In real life, robots are mainly used in factories. They do many different jobs. Usually these jobs are too 1, difficult or boring for humans.

Robots also help disabled people and people who cannot look after 2. For example, scientists are making a robot to help 3 people. Now many of them have a dog to help them. The dog is called a guide dog. In the future, guide dogs might be robot dogs.

One robot dog is called Meldog. It has wheels. It usually "walks" 4 its owner. It is very clever. It knows the speed of its owner's walk. Meldog talks to its owner by 5. The owner wears a special belt. This belt 6 instructions to the owner from Meldog such as "Stop here", "Turn left" and "Turn right".

    In the United States, another 7 of robot helps disabled workers. This robot, called Kilroy, helps disabled computer operators. The robot 8 the sound of its owner's voice. It follows instructions such as "Turn the page" and "Make a cup of coffee".

    Robots are also used in American 9. They can do simple jobs. For example, they shave (刮脸) patients and brush their teeth and take meals from the kitchen to patients' rooms. It never gets lost 10 this robot has a map of the hospital in its computer memory.