B

    No Car Day was first started by 34 cities in France on September 22, 1998. It was started to protect the environment. By now, more than 1,000 cities around the world have had a No Car Day.

    The first No Car Day in China was in Chengdu in 2001. Other cities including Taipei, Shanghai and Wuhan, also support the day.

    In Beijing, more and more people are taking part in the activity. It asks drivers to leave their cars at home for one day each month and walk or ride a bike to work. It also calls on Beijingers not to use cars on June 5th (World Environment Day). The slogan for the day is, "If we drive for one less day, we can have one more nice day."

    So far, more than 200,000 drivers have shown their support. "We can't control the weather, but we can choose not to drive," said Wu Zhonghua, a car club chairman. Beijing is trying to have 238 blue sky days this year. In the first quarter of 2007, Beijing only had 52 blue sky days. This was 11 days less than the number for the same period last year. Much of the dust comes from the desert, but cars cause most of the air pollution. We must do more for No Car Day.

    Sitting too much is now listed with smoking and junk food as a bad habit that increases your risk of heart disease.

    New Australian research shows that half-an-hour in the gym will not make up for the waist-expanding damage caused by spending the rest of the day sitting.

    But the good news is that doing chores(家务杂事) in the house or gently walking around the office while on the phone might be enough to keep you fit.

    The study joins the growing body of evidence suggesting too much sitting might undo the benefits of exercise.

    The study measured the intensity(强度)of physical activities in 168 subjects over seven days. If found that, regardless of how much exercise they did or their total sitting time, those who took more breaks from sitting had lower risk of thick waists and lower levels of blood lipids(脂质).

    “Higher levels of blood lipids have been linked to a heightened risk of heart disease,”principal researcher Genevieve Healy of the University of Queensland said. "What the study shows is that there are benefits in just getting up regularly and interrupting your sitting time."

    Researchers behind the Stand up Australia project have written to the Rudd Government requesting $ 3.5 million for a two year study into how long sitting affects the health and productivity of workers.

    The latest study builds on work that is shifting the health promotion focus from purposeful exercise, such as running, to lower intensity activities throughout the day.

    The Australian research bas been backed up US studies, which show standing up is enough to double the metabolic(新陈代谢) rate and the amount of calories burnt.

    “To hold a body that weighs 77kilograms upright take a .fair amount of energy from muscles", said professor Marc Hamilton from the University of Missouri. "There is a large amount of energy associated with standing every day that cannot be easily replaced by, 30 to 60minutes in the gym."

    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 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 Earth—in other solar systems. These planets might have intelligent life.

    Have beings from space already visited Earth? "Probably not," says Shostak. "It's a long way away. However, intelligent beings may contact us in other way, 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."

    How do you deal with plastic bags from the supermarket? Throw them away or recycle them? How about eating them?

    The bags are not harmful to the environment, Humans and animals can safely eat them. Indian company EnviGreen has made a bag with natural materials. It looks and feels just like plastic, but can break down(分解) easily.

    Ashwath Hedge who set up the EnviGreen Company spent four years doing experiments(实验) with 12 natural materials. They include potato, corn, vegetable oil and banana. He made the materials into liquid(液体) and used the liquid to make the bag.

    Although the EnviGreen bag is more expensive than a common plastic bag, it has many advantages. According to the Wall Street Journal, it takes 1,000 years for common plastic bags to break down. But an EnviGreen bag can naturally break down in less than 180 days. It also breaks down in less than a day in water, and in less than a minute in boiling water. Hedge was happy to show it in his interview, he put an EnviGreen bag in water and ate it with a smile.

    There are more than 15,000 tons of plastic waste in India every day. But only 9, 000 tons are processed. In China, 3 billion plastic bags are used every day. Maybe the EnviGreen bag could be a solution(解决方法) to the world problem of plastic pollution.

Hello, I'm Bob. I'm 12 years old. I am at school now. I want to say something about myself. 

Playing volleyball is my hobby. I like it very much. I always play volleyball with my friends after school. It's relaxing for me. I have five volleyballs. They are under my desk. And I like to watch volleyball games on TV. 

I have eggs, milk and some fruit for breakfast. For lunch, I have noodles and some salad(沙拉). For dinner, I like chicken and some vegetables. I don't eat ice cream. It's not healthy. My favourite food is fruit and vegetables. I think they are good for our health. 

I'm healthy because I like to play sports and eat healthy food. What about you? Can you tell me about your hobby and eating habits?