Robots seem to be getting cleverer and cleverer. Here are four examples.

    Endangered dolphins are beautiful animals that needed to be saved. It may interest you to know there are about six different types of dolphins that are endangered. Many of them are river dolphins and they are very close to being lost forever if we do not take the time to care for them. The following is the reason why they are in danger.

    {#blank#}1{#/blank#}Dolphins can often get stuck(卡) in these nets and they may die. Another problem is the fact that many people and different countries will hunt for dolphins as food.

    {#blank#}2{#/blank#}When the oceans and rivers are polluted, it affects the very environment where these beautiful creatures are living. It may be important to also keep in mind that the dolphin is towards the top of the food chain.{#blank#}3{#/blank#} If these small animals are affected by the pollution as well, there really is no safe place for the dolphin to go.

    {#blank#}4{#/blank#}You can also pay attention to the land around you. Do not litter and stop if you do. Spend time on the weekend cleaning up trash in your area and recycle what you can. You play a large role in this whether you believe it or not. So, find out what your role is related to endangered dolphins and work towards a positive change.

    Is there intelligent（有智力的） life on other planets? For years, scientists said "no" or "we don't know". But today this is changing. Seth Shostak and Alexandra Barnett are astronomers（天文学家）. They believe intelligent life exists（存在） somewhere in the universe. They also think we will soon contact these beings（人生物）.

    Why do Shostak and Barnett think intelligent life exists on other planets? The first reason is time. Scientists believe the universe is about 12 billion years old." This is long enough for other planets to have intelligent life," say Shostak and Barnett. The second reason is size-the universe is huge." Tools like the Hubble Telescope（哈勃望远镜） have shown that there are at least 100 billion galaxies," says Shostak. "And our galaxy, the Milky Way, has at least 100 billion stars.

    Some planets going around these stars might be similar to the Earth."

    In the past, it was hard to look for signs of intelligent life in the universe. But now, powerful telescopes（高倍望远镜） allow scientists to discover smaller planets-the size of Mars or the Earth-in other solar systems. These planets might have intelligent life.

    Have beings from space already visited the Earth?" Probably not," says Shostak. "It's a long way away. However, intelligent beings may contact us in other ways, such as radio signals（信号）. In fact, they may be trying to communicate with us now, but we don't have the right tools to receive their messages. However, this is changing. By 2025, we could make contact with other life forms in our universe and we might help each other."

    Every day there is less and less space on Earth for rubbish. Yet every day we make more and more rubbish. What can we do? We can recycle some of our rubbish. Recycling means that the rubbish will be made into something that can be used again.

    Recycling helps Earth. And it saves space in rubbish dumps. Half of everything that we put into landfills could be recycled instead. In fact, most things made of paper, metal, glass and plastic can be recycled.

    Paper can be broken into small pieces and made into new paper. Steel and aluminum cans(金属雄)can be melted down(熔化)and made into new cans. The same is true of glass bottles. This can be done over and over again. Recycling doesn't take as much energy as making these things the first time. So we can use less of Earth's fuel resources.

    Plastic can be melted down, too. Then it can be formed into park benches, playgrounds and so on. Some people call plastic the "wood" of the future. Things made of plastic will last about 400 years-even if they stay outside in the weather. No wood can do that!