We have known for a long time that flowers of different plants open and close at different time of day. Yet no one really understands why flowers open and close like this at particular times. It is not as simple as we might think, as new experiments have shown. In one experiment, flowers were kept in darkness. We might expect that the flowers, without any information about the time of the day, did not open as they usually do. In fact, they continued to open at their usual time. This shows that they have some mysterious (神秘的) way of knowing the time.

    Their sense of time does not depend on information from the outside world; it is, so to speak, inside them, a kind of “inner clock”. This discovery may not seem to be very important. However, it was later found that not just plants but also animals including man have this “inner clock” which controls working of their bodies and their activities.

Human beings, then, are also controlled by this mysterious power. Whether we wish it or not, it affects such things in our life as our need for sleep, our need for food. And our ability to concentrate(集中).

What will the weather be like? Some people say they can know what the weather will be like from birds. They kook at birds. When they see birds fly high out to the sea, they say it will be a nice day. For birds donˈt like to fly out when it could rain. When the weather will be bad, sea birds turn back and stay on shore.

A big wind may come with a rain. Birds do not like to fly in a big wind. They may sit in a tree when rain is on the way.

Some people look at different animals on a farm. Other animals can alsotellthe weather. A chicken may make a big noise when rain is on the way. It may run here and there. A frog can show the weather, too. A frog will make a big noise when rain is on the way. It will stay in the water. On a nice day, it will come out up high out of the water.

“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（公元） 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, 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 happy do you feel?

Inventions have speeded up our lives so much that they often leave up 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 often seem to be happier? Perhaps because they live simpler lives.

One 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（微波炉）, computer or mobile phones.

The grandmother, Lyn, said, “The more things you have, the more difficult life becomes.” The boys said they fought less. Probably, they said, because there was less to fight over, such as their computer. Benjamin also noticed that his grandmother had changed from being a “trendy（赶时髦的）, beer-drinking granny”, to one who cooked things.

根据短文内容，选择正确答案。

More and more people like bicycling and it is no surprise. It is fun, healthy and good for the environment（环境）. Maybe that’s why there are 1.4 billion bicycles and only 400 million cars on roads worldwide today. Bikes can take you almost anywhere, and there is no oil cost!

Get on a bicycle and ride around your neighborhood. You may discover something new all around you. Stopping and getting off a bike is easier than stopping and getting out of your car. You can bike to work and benefit（受益）from the enjoyable exercise without polluting the environment. You don't even have to ride all the way.

Folding（可折叠的）bikes work well for people who ride the train. Just fold the bike and take it with you. You can do the same on an airplane. A folding bike can be packed in a suitcase. You can also take a common bike with you when you fly. But be sure to look for information by getting on airline websites. Not all airlines are bicycle-friendly to travelers.

Health Benefits of Bicycling:

It helps to prevent heart diseases.

Bicycling helps to control（控制） your weight.

A 15-minute bike ride to and from work three times a week burns off five kilos of fat in a year.

Bicycling can improve your mood（心情）.

Exercise like bicycling has been shown to make people feel better, more relaxed and self-confident.

Bicycling is healthier than driving.

A workmate of mine lives in the same street as me. He drives about 5 kilometers to work every day while I cycle the same distance almost every day. I must say that I ocassionally(偶尔)take the car if the weather is bad, or I ‘m very tired or in a hurry. Imagine my surprise when I cycled to work one day, went for a shower in the sports center and saw my neighbour in the gym on the cycling machine after driving to work! I share an office with another workmate who lives near to me, she drives to work every day, and the end of the day, she drives to a gym. I don’t see the logic(逻辑). It would be much easier to cycle to work so that you have some exercise every day as part of your daily routine.

  I try to advise them to cycle to work, so I did some research about the benefits of cycling to work. Of course, cycling has some advantages over driving. It’s cheaper and it’s better for the environment, and you don’t have to find a parking space. The point about parking space is an important one as the car parks are often full. I know that my workmate sometimes spends 15 minutes looking for a parking space! It’s true that cycling is a little slower than going by car, but at rush hour it doesn’t make much difference. The time it takes to cycle is generally easier to predict than the time it takes to drive. When there is heavy traffic, people on cycles can get past, while people on cars have to wait.

  There are clear health benefits to cycling. According to one expert, if you cycle regularly you should be as fit as a younger person. I ‘m 47 and I still play football in a team, so I would say that his opinion is true. As well as being good for your health, cycling can reduce your stress. I also find that when I can’t solve a problem at work, the answer often comes to me when I’m cycling. Sometimes the harder you think about a problem, the harder it is to find the solution. And you really need to pay less attention to the problems. Cycling relxes the mind.

  I am going to say to my workmates—“two wheels good, four wheels bad” every day until they get on their bikes!