A crow(乌鸦) is about twenty inches (英寸) long and black all over. Crows are dirty birds because they live on bad food. Crows eat a lot of waste food. In this way they are more useful to us than any birds. They clean up the dirty things in our streets. Crows are always hungry. They look for food all day, and in the evening you can see them in large numbers flying back to their nests(巢) in the trees. They sleep there at night.

    Crows are much noisier than other birds. Very often a large number of crows will get together on one house and talk. Sometimes they talk together, and sometimes they do it by turns(轮流) like human beings(人类). It is easy to tell(判断) from crow's sound if they are pleased or angry. Perhaps crows talk a lot because they are friendly birds. A pair of crows will live together all their lives, and if one of them dies, the other one becomes very sad and quiet for the rest of its life and some time later it dies too.

    A long time ago, people thought that the Sun went round the Earth. In some countries people even said that the Sun was a god (神). They thought the god drove across the sky each day on a golden horse. Now we know the Earth goes round the Sun. It takes the Earth a year to go all way round the Sun. Today men even know how far it is for the Earth to go round the Sun. They tell us that the Earth travels over a thousand miles a minute on its journey round the Sun.

    The Sun is really a star. It is much bigger than the Earth and it is very hot. Some people have been to the Moon but we know that no one can ever go to the Sun. It is far too hot for people to live anywhere near it. The Sun is about three hundred thousand times heavier than the Earth and more than a million times larger.

    Recently, many people have begun to try a new way of shopping through the Internet. They are very interested in it. Why is it becoming more and more popular now? There are some reasons. First, more and more people have their own computers and their computers can be joined with the Internet. So it is possible for many of them to do some shopping through the Internet. Second, shopping through the Internet can save some money and a lot of time. Third, they don't need to go to the shop themselves, Because of these good facts, few people refuse it.

However, some people don't like this new way of shopping. They are worried about the safety of shopping online, Customers can only see the pictures of a product on the Internet. And they can't enjoy the pleasure of buying things in a large supermarket or a wonderful shopping centre. These are the reasons why they do not like it.

    But I think more and more people will like this new kind of shopping in the future.

    In many places the weather changes during the year. These changes are called seasons. In the north and south there are four seasons in a year. At the North and South Pole, there are only two seasons. In tropical (热带) places near the Earth's equator (赤道), there are two seasons: a 'wet' season and a 'dry' season. Each season brings changes. They are important for plants and animals that live in different parts of the world.

    Spring starts when the day and night are the same length. The weather gets warmer and sunnier. Trees and plants start to grow. Many animals have their babies in spring.

    Summer begins on the longest day of the year. In the north this is on June 21 or 22. Summer is usually the warmest and sunniest time of the year. Fruit grows faster on trees and plants. Young animals grow bigger and stronger.

    Autumn starts when the day and night are the same length again.

During autumn, the leaves change color and fall down from the trees. Some animals collect food before winter comes.

    Winter begins on the shortest day of the year. In the north this is on December 21 or 22. The weather is colder and in some places there is lots of snow. Plants and trees stop growing. Some animals, like bats and bears, find places to hide and sleep. This is called hibernation.

    Mobile Apps are part of our daily life. Here are some of the most popular Apps.