We know the earth is a planet．There are seven other planets，and they go  1 the sun together．The eight planets and the sun are2 the solar system．The first planet，3   the sun，is Mercury(水星)．It is 58 miIlion  4  from the sun．Venus(金星)is the second planetfrom the sun，and  5 planet，the earth，is the third．It is from the sun,and 55  planet,the earth,is the third.It is 2,650 million kilometres from the sun．

    Jupiter(木星)，Saturn(土星)，Neptune(海王星)and Uranus(天王星)are all 6 than the earth，7 Venus，Mars and Mercury are smaller than the earth．

    Animals，trees and humans can only 8  on the earth，because the other planets in our solar system don't  9  air or water．Do any  10planets in   solar systems have life?We don't know about it．

    Animals are our friends. We can find1different kinds of animals. Some animals are living 2 big woods(森林). And some animals are living with 3. Animals are very4 to people. People can teach the elephant to do some heavy 5. And they can also teach the dog to 6the house. A watch dog is very 7 It can help people in danger(危险). So people 8dogs very much. Most of9like to go to the zoo.10there are many animals in zoos. Zoo is a good place for children to get to know animals.

    In 2045, I will live in a smart house. It won't be very1, because the earth will be more crowded in thirty years, and there won't be much room for me to2my house. But it will be comfortable and full3smart furniture (家具). In the morning, my bed will “stand up” and wake me up.4I don't need an alarm clock. After I take a shower and then go into the5, my breakfast is already ready.6cooks it? My smart table does.

    I will spend the daytime in my office. But I can still know what is 7in my house. Is there8visiting me? Does my dog do well alone at home? I can watch all of these on my phone.

    When I arrive home in the evening, the lights will “know” I'm back and they will9themselves. I10I will have such a cool house. Do you think so?

    Australia is one of the largest countries in the world. It is 1 smaller than China. It is in the south of the earth. Australia is big, but its population is 2. The population of Australia is nearly as large as that of Shanghai.

    Enough laws have been 3 to fight against pollution. The cities in Australia have got little air or water pollution. The sky is blue and the water is 4. You can clearly see fish swimming in the rivers. Plants5very well.

    Last month we visited Perth, the biggest city 6 Western Australia, and went to a wild flowers' exhibition(展览 ). There we saw 7 large number of wild flowers we had never seen 8. We had a wonderful time. Perth is9 for its beautiful wild flowers. In spring, every year Perth has the wild flowers' exhibition.10visiting Perth, we 11 a day in the countryside. We sat down and had a rest near a path at the foot of a hill. It was quiet and we enjoyed ourselves. Suddenly we heard bells ringing at the top of the hill. What we saw made us 12all our things and run back to the car as quickly as we could. There were about three hundred sheep 13towards us down the path.

    Australia is well-known for its sheep and kangaroos. After a short drive from 14 town, you will find yourself in the 15of white sheep. Sheep, sheep, everywhere are sheep.

    It's March 12^th. Li Li and Lin Tao are digging on a hill nor far from their school. In China, people across the country plant trees1on this day.

    The idea of planting trees was first put forward in 1911 by Sun Zhongshan, the great2 in China's history. He said more trees were needed as a3against flood(洪水)and drought. In 1915, April 5^th was named as Tree Planting Day. Then, in 1979, the day4to March 12^th, to 5the date on which Sun Zhongshan died.

    "Everyone has heard of the Great Wall of China," says Li Li. "But have you heard of the Green Wall of China? That's the biggest tree planting 6 of all. "The Gobi Desert in the north of China was 7every year. So in 1978, a tree planting project was started to 8 Gobi spreading. The government and local farmers have been planting millions of trees to build a great green "wall" along the edge of the desert.

    "Tree planting has become a tradition in China now," says Lin Tao. "Almost everyone does it on March 12th. Many people also plant a tree on a 9 day. My parents planted a tree when started school. And my cousin planted 10 on his wedding (婚礼) day. We do it for the environment and for ourselves."