Can animals be made to work for us? Some scientists think that one day animals may be taught to do a number of simple jobs. They say that in a film or on TV .We may see elephants, or monkeys, dogs, bears, or other animals doing a lot of things. If you watch carefully, you may find that those animals are always given something to eat in return(作为回报) for doing them. The scientists say that many different animals may be taught to do a number of simple jobs if they know they will get something to eat in return.

    Of course, as we know, dogs can be used to guard a house, and elephants can be used to do some heavy jobs. And we can also teach animals to work in factories. Apes(猿猴), for example, have been used in America to help make cars and scientists believe that these large monkeys may one day get in crops(收割庄稼) and even drive trains.

    Thanks to the Earth, we have fresh air to breathe, clean water to drink and warm sunshine to enjoy. But it seems that we haven't realized that the Earth is facing many environmental challenges and it is getting "sick".

    Scientists say that of all the environmental challenges, climate (气候) change is the biggest one. The temperature on the Earth has risen by more than 0. 5C since 1992. Cities like Singapore and Tokyo that are at low altitudes (海拔) may be covered by the ocean (海洋) in the future.

    But this is not the only problem people are facing. Since 1992, the human population has grown by 2 billion, while the population of all other animals has dropped by nearly 30 percent. At the same time, water pollution has become serious. We are also facing problems like light pollution, noise pollution and some other pollution.

    However, we have made some progress in saving the Earth. For example, we stop using harmful materials to make the hole in the ozone layer (臭氧层) smaller to slow the rise of the temperature. We do a lot of work to help the animals in danger, or more than two-thirds of the worlds wild animals may disappear (消失) by the end of 2020.

    "The progress shows that we can make good changes when we act wisely, "scientists say, "we must take action to protect the environment, or it will be worse."

    "Life is speeding up. Everyone is getting unwell."

    This may sound like something someone would say today. But in fact, an unknown person who lived in Rome in AD 53 wrote it.

    We all love new inventions. They are exciting, amazing and can even change our lives.

    But have all these developments really improved the quality of our lives?

    Picture this: You're rushing to finish your homework on the computer. Your mobile phone rings, a QQ message from your friend appears on the screen, and the noise from the television is getting louder and louder. Suddenly the computer goes blank and you lose all your work. Now you have to stay up all night to get it done. How calm and happy do you feel?

    Inventions have speeded up our lives so much that they often leave us feeling stressed and tired. Why do you think people who live far away from noisy cities, who have no telephones, no cars, not even any electricity(电) often seem to be happier? Perhaps because they lead simple lives.

    Our family in the UK went "back in time" to see what life was like without all the inventions we have today. The grandparents, with their daughter, and grandsons Benjamin, 10 and Thomas, 7, spent nine weeks in a 1940s house. They had no washing machine, microwave, computer or mobile phones.

    The grandmother, Lyn, said, "It was hard physically, but not mentally." She believed life was less materialistic(物质的). "The more things you have, the more difficult life becomes," she said. The boys said they fought less. Probably, they said, because there was less to fight over, such as their computer. Also Lyn changed from being a "fashionable, beer-drinking granny, to one who cooked things."

    Here are some simple ways to beat the stress often caused by our inventions!

    Don't be available all the time. Turn off your mobile phone at certain times of the day.

    Don't check your emails every day.

    Don't reply to somebody as soon as they leave a text message just because you can. It may be fun at first, but it soon gets boring.

    Make sure you spend some time talking to your family. Set aside one evening a week when you don't turn on the television. Play cards and chat instead.

    Get a low technology hobby. Every day, do something in the old way, such as walking to have a face-to-face meeting instead of using the email or telephone.

    Don't worry too much about life—laugh more.

The weather is getting hotter and hotter. You are thirsty playing basketball or riding home from school. A cold drink may be just the thing. But be careful what you are drinking. Something that looks cool may not be good for your health.

There are plenty of "energy drinks" advertisement on TV. Most of them have beautiful colors and cool names. They tell you they are helpful to your health. Sounds great and lots of people believe them!

But after a careful check you may find that most energy drinks have lots of caffeine (咖啡因) in them. These drinks are especially aimed at young people, students, busy people and sports players. Makers sometimes say their drinks make you better at sports and can keep you awake. But he careful not to drink too much.

Caffeine makes your heart beat fast. Because of this, the International Olympic Committee has limited (限制) its use. Caffeine in most energy drinks is as strong as that in a cup of coffee or tea. Possible health dangers have something to do with energy drinks. Just one box of energy drink can make you nervous, have difficulty sleeping and can even cause heart problems. Scientists say that teenagers should be discouraged from taking drinks with a lot of caffeine in them.

Do you know many students aren't healthy?

Now many students know sports are good for their health. {#blank#}1{#/blank#} Some of them only watch them on TV. What's more(而且), many of them only like watching TV and playing computer games. They often say, "{#blank#}2{#/blank#} Play basketball? Oh, it sounds difficult. "

{#blank#}3{#/blank#} They don't have carrots for lunch and they don't have tomatoes for dinner. But vegetables and fruit are healthy food. {#blank#}4{#/blank#} But they like junk food (垃圾食品). {#blank#}5{#/blank#}

If (如果) you would like to be healthy, eat vegetables and play sports every day.