Canada 4:00 a.m. to 8:00 a.m.

    Canada is a big country with six time zones. In the west, it is four a.m., and everyone is asleep, but in Halifax on the east coast it is eight o'clock and people are having breakfast. It is a cold Friday morning in November, and the temperature is ten degrees below zero Centigrade(度).
Argentina 9:00 a.m.
    In Buenos Aires, the capital of Argentina, it is nine a.m. on a warm summer morning, and people are starting work or school. November is a summer month in Argentina because it is in the southern hemisphere(半球).
Scotland 12:00 noon
    Scotland is part of the United Kingdom. The capital of Scotland is Edinburgh, and the capital of the UK is London. It is twelve noon, or midday, in Edinburgh. Children are having lessons, but they are looking forward to the weekend because there is no school on Saturday and Sunday.
Egypt 2:00 p.m.
    Friday is already the weekend in Egypt. Friday is a special day for Muslims, so schools, offices and shops are closed in all Arab countries. So now, at two p.m., most people in Egypt are having lunch with their families.
Japan 9:00 p.m.
    Japan is seven hours ahead of Egypt, so it is already Friday evening there. The weekend is beginning. Most people are out with friends or watching television or playing computer games.
New Zealand 12:00 midnight
    It is late on Friday night, so most people are asleep. Now Saturday morning is arriving. It is morning in Canada too, but that is Friday morning!

    Although cats may be one of the most popular pets today, little is known about how and when humans and cats set up their close relationship.

    The earliest evidence for human–cat interaction dates back to prehistoric Cyprus(史前塞浦路斯), where the remains of a wild cat and a human — dated 9,500 years old — were found buried together

A new study in the Proceedings of the National Academy of Sciences has confirmed the first direct evidence of a human–domestic cat relationship among Chinese farmers 5,300 years ago. Researchers studied the bones of cats, dogs, deer and other animals unearthed in an excavation (挖掘) near a village in Central China. By using some ways, scientists showed that the cats were living on a mostly millet(黍)–based diet, just like the domesticated dogs and pigs from the site.

"The most reasonable explanation for a high consumption of millet–based food is that the cats had formed a stable and mutual relationship with humans and could easily feed on rodents (啮齿动物) around human villages, find leftover food or even have been fed by people intentionally," said Hu Yaowu from the Chinese Academy of Sciences in Beijing, whose research focuses on the relationship between humans and domesticated animals.

    "It is very interesting for us to find the consumption of millet-based foods by the cats, since this kind of evidence had long been missing.” Hu explains. Since cats usually eat meat, such a diet would be unexpected, unless the cats were being fed by people, the study argues. The researchers also found that one of the cats survived to reach old age, implying that it had a safe place to live and enough to eat.

Why the farmers wanted to keep cats nearby or make them "pets" could be answered by other evidence. Chinese archaeologists found some storage containers were specifically designed to keep out rodents — a vermin (害兽) that cats could certainly have helped with.

The simplified theory is that rats were attracted to the food of farmers, and so were harmful to farmers. Cats were attracted to the rats, and so farmers formed a mutually beneficial relationship with cats, taking care of them in return for pest control.

A

    Everyone knows that exercise is important. It makes your heart and body strong. But you need to know the following.

*Get your body ready!

    Before you do any exercise, be sure to warm up for at least five minutes. During warming up, you should stretch(伸展) all parts of your body.

*Exercise enough, but not too much.

    It's good to exercise twice each week. Thirty minutes each time is enough. Try all kinds of things until you find one, two or even three sports that are right for you.

*Exercise at fitness centres.

    There is a lot of equipment(设备) at fitness centres. The equipment will help exercise your arms, legs and other parts of your body to make you fit. Some people buy equipment. But it is very expensive.

*Stop playing when you are hurt!

    If you get hurt when you are doing exercise, don't play again until you are well.

*Don't get thirsty!

    Drink a lot of water when you are playing sports because it is easy to become thirsty.

    Some animals sleep during the wintertime because the weather can be very cold and it is difficult for them to find food. They can sleep for a long time. This kind of winter sleep is called “hibernation”.

    If an animal moves about a lot, it needs food. Hibernating animals do not need to eat much because they are not moving about. Their hearts(心脏) beat very slowly and they also breathe(呼吸) slowly. They find a place that is sheltered(遮蔽的) from bad weather and where they are out of danger. Their body fat(脂肪) keeps them alive and warm.

    Some animals, such as bears, may wake up from their hibernation on warm winter days and then quickly go back to sleep again when they see the snow is still thick on the ground. When the weather becomes warmer in spring, the animals start to wake up and look for food.

    In 1845, a deadly disease struck the farms of Ireland, killing all the Lumper potato plants. In another place or time, the death of single crop species (物种) might not have been so important. But in Ireland, in 1845, people depended almost solely on the potato for food. The death of one species caused a terrible famine(饥荒). Now, some scientists are worried that such a famine could happen again, but on a much wider scale.

    Over the centuries, farmers have discovered thousands of different species of food crops. Each species has special qualities. Some can be grown in very hot or cold climates. Others are not affected by certain diseases. However, you won't find many of these species in your local supermarket. To feed the seven billion people on Earth, most farmers today are growing only species of plants and farming only species of animals that are easy to produce in large numbers.

    For example, in the Philippines, there were once thousands of varieties of rice: now fewer than 100 are grown there. In China, 90 percent of the wheat varieties grown just a century ago have disappeared. Scientists believe that over the past century, we have allowed more than half of the world's food varieties to disappear.

    One solution to this problem is to collect and store the seeds (种子) as many different plant varieties as we can before they disappear. The idea was first suggested by Russian scientist Nikolay Vavilov. In the 1920s and 1930s, he collected around 400,000 seeds from five contients. More recently, others are continuing the work he began.

    In the U.S. state of Iowa, Diane Ott Whealy wanted to protect historic plant varieties, like the seeds her great –grandfather brought to the U.S. from Germany more than a hundred years ago. She and her husband started a place called Heritage Farm, where people can store and trade seeds.

    More importantly, the people at Heritage Farm don't just store the seeds; they plant them. By doing this, they are reintroducing foods into the marketplace that haven't been grown for years. These food species are not just special in terms of appearance or taste. They also offer farmers food solutions for the future, from the past.