Ladies and gentlemen, I returned to this year in a time machine. In the year 2500, we are able to travel through time to any year in the history of the earth. This year is your last chance your lifestyle to save the earth.

    Beginning in the middle of the 20th century, a few people were worried about polluting the earth's water and air, but most people did not change their way of life. Instead, they continued to pour(倒) dangerous chemical(化学物品) and other waste into lakes and seas, to drive more and more cars and trucks, and to cut down trees.

By the year 2200, the earth's water was completely polluted. People could no longer drink water, and they had to use other types of liquids(液体). Scientists said that in the future there might be too many people on the earth. But not enough was done.

So by the year 2300, there were so many people that food became scarce. There was no water to grow food and all of the fish in lakes and seas died because of pollution. Terrible wars broke out between the rich and the poor. Scientists were working very hard to find another planet in space where humans could live.

By the year 2400, the air was too polluted for humans to breathe. So we had to leave the earth. But only the rich were able to leave. Where did we go? Nowhere. And everywhere. You see scientists did not find another safe planet, so now we must travel around the universe in our space ships. We are still looking for a place to call our home.

    So it is up to you to change history. There is still hope. You must change your lifestyle now, before it is too late.

    Scientists have always believed that snails are not able to find their way home. But Briton Ruth Brooks, a retired teacher, has found that it is not true.

    Brooks began an experiment on snails after she got mad with the snails in her garden.

    The snails had eaten her vegetables. She didn't want to kill them, so she took them to another place. But she found they always seemed to come back.

    Brooks did an experiment. She marked the snails in her garden with nail polish(指甲油).

    She placed the snails in the area around her home and made notes of their movements.

    She found that snails have a strong homing instinct (本能); the longest returning snail traveled back 90 meters. Brooks has been named Britain's best amateur (业余的) scientist after her work won the BBC Radio 4 project, So You Want To Be A Scientist.

    She said, "I've always wanted to know whether the snails that eat my plants just come back when I move them, and if they do, what is their homing distance?

    "I would say on the evidence (证据) that it would be safe to take your snails away beyond 100m or even further. If you put them somewhere nice with some food, you can be almost certain that they won't come back."

    Is your TV connected to the Internet? What about your chair, or your fridge? Probably they are not. But in the future, most things in your home may be connected, as the so-called "Internet of things" is developing.

    The Internet of things may be coming sooner than you think. In 2015, Samsung CEO spent a lot of time talking about the Internet of things. He said that in the next five years, every Samsung product will be part of the Internet of things, whether it's a vacuum cleaner or a washing machine.

    So, how do household objects that are part of the Internet of things work? Well, think of a common chair. When connected to the Internet, the chair warms up when it knows that the user has just walked into the room and is feeling cold.

    An Internet-connected camera could help people feel safer in their homes. It can recognize people's faces, and even can see when someone passes by and send you a message on your smartphone to let you know who's there. If the person is someone you don't know, it can tell you that, too.

    But according to MIT Technology Review, whether companies are connecting dog food bowls or security systems to the Internet, there may be some problems. For example, many early connected-home devices (装置) don't have much built-in security, which means they could be hacked (被黑客攻击). In addition, it could be difficult to get these devices to work together especially when they are made by different companies. To fight this, many companies have joined the Open Connectivity Foundation, which has more than 300 members now.

    So, picture this: you enter your home. The temperature changes to make you feel comfortable. Your favourite music starts playing for you. Do you think that this would be a good thing? It may happen sooner than you think.

    As we know, all living things have to eat food. For a man, a tiger, a fish, a bird, or even a worm, food is needed. We know all living things are sure to die without food. In every part of the world, different kinds of animals share living places and live in communities (群落) together. They are connected(联系) in a food chain.

    In a food chain, some living things are producers and some are consumers. Plants are producers because they use sunlight, soil and other things to make their own food. Animals are consumers because they have to eat other animals or plants.

    There are four different kinds of consumers in the animal world. A carnivore is an animal that only eats other animals. An herbivore is an animal that only eats plants. An omnivore is an animal that eats plants and animals. A scavenger is an animal that eats dead animal.

    Here is a picture of a food chain. The food chain shows how animal eat each other in a community. In the picture, you can see what animal or plant is food for another animal. See? The grass is food for a rabbit(兔子), which then becomes food for a hungry tiger. In this way, all of these animals are connected.

Do you feel guilty(内疚的) for something you did? Maybe you made a mistake that hurt someone. {#blank#}1{#/blank#} Either way, the simple words "I'm sorry" can help you and others feel better. It's not always easy to admit(承认) what you did is wrong. But you can't learn from your mistakes without admitting them.

Apologizing(道歉) is an important part of personal growth. When you apologize, the other person knows that you understand his feelings. {#blank#}2{#/blank#} But in fact, it shows that you are strong enough to put others before yourself. After apologizing, you may become closer to your friend than before.

But even after you decided to apologize, you may not be sure how to do it. {#blank#}3{#/blank#}

①Show that you feel guilty and understand how the other person feels. For example, you could say, "{#blank#}4{#/blank#} I feel terrible for talking to you like that."

②Don't keep doing what you apologized for.

③Don't put off(推迟) making an apology.{#blank#}5{#/blank#}

Apologies can be hard, but they are necessary for healthy relationships.