We often read the Air Quality Index （空气质量指标） or AQI reported in the newspaper. The AQI helps us understand what the air quality around us means to our health. The AQI uses colors, numbers and words to tell us about the air. Let's see what these colors and numbers mean.

    Why do plants grow in some places but not in others? Why does some land have so many plants growing on it, while other land has almost no plants growing on it at all?

    To grow, plants need several things. One is warmth. In very cold places almost nothing grows. Plants also need water. In very dry parts of the Earth only a few unusual plants can grow. That's why there are almost no trees or grass in dry deserts.

    Plants must also have a place to put down their roots and grow. They find it difficult to grow on hard land. The town is built(被建立) on hard land. The plants there have only the soil between the cracks of the stones to grow in.

    Another thing plants must have before they can grow is food. What will happen if we try to make things grow on the sandy beach? A few plants, such as grass, will grow in sand, but most plants won't. Even if the weather is warm enough and we water the plants each day, many of them will die because the sand on this beach has almost no food for plants.

    Different weather makes people feel different. It influences health, intelligence（智力）and feelings.

    In August, it is very hot and wet in the southern part of the United States. People there have heart trouble and other kinds of health problems during this month. In the Northeast and the Middle West, it is very hot at some times and very cold at other times. People in these states（州）have more heart trouble after the weather changes in February or March.

    The weather can also influence intelligence. For example, in a 1983 report by scientists, IQ（智商） of a group of students was very high when a very strong wind came, but after the strong wind, their IQ was 10%lower.The wind can help people have more intelligence. Very hot weather, on the other hand, can make it lower. Students in many schools of the United States often get worse on exams in the hot months of the year（July and August）.

    Weather also has a strong influence on people's feelings. Winter may be a bad time for thin people. They usually feel cold during these months. They might feel unhappy during cold weather. But fat people may have a hard time in hot summer. At about 18℃, people become stronger.

    Low air pressure（气压） may make people forgetful（健忘）. People leave more bags on buses and in shops on low-pressure days. People feel best at a temperature of about 18℃.

Are you feeling sad, tired, forgetful, or unhappy today? It may be the weather's problem.

    Pisces is the twelfth star sign. There is a legend about its name.

    Long, long ago, there was a war between gods and a bad monster (怪物). It lasted ten years. One day, the gods were surprised to find that the monster was coming towards them. The goat god Pan shouted a warning and tried to change himself into a fish. One god, Aphrodite, took her little boy Eros and tried to hide among the bushes near Euphrates River. She was the god of love and her son was the god of war. It is said that two fish swam to carry Aphrodite and her child to safety. Some people also believe that Aphrodite and Eros changed into fish themselves and swam away to safety. Later the fish represent Aphrodite and her son Eros.

    As they appeared in the sky, the two fish were tied together by a rope (绳子). Some said that Aphrodite tied the little boy to her body so that he would not get lost as they swam away to safety. That's the story about Pisces.

    In Western countries, some people believe people will share similar characteristics if they have the same star sign. So if you're born between February 19th and March 20th, your star sign is Pisces. It means that you are generous, easy-going and creative.

Li Hua：Lily，welcome to Chengdu!Did you watch the opening ceremony（开幕式） of the 31^st Chengdu FISU World University Games on July 28th？

Lily：Of course. It was so amazing that I was{#blank#}1{#/blank#}surprised at it!When sportsmen and sportswomen from home and{#blank#}2{#/blank#} came to show at the opening ceremony，audiences burst into cheers. 

Li Hua：What's more，they weren't the only ones that appeared in it. Students from many universities in Sichuan {#blank#}3{#/blank#}to work for it without being paid. Most of them{#blank#}4{#/blank#}service and comfortable environment for these sportsmen and sportswomen. 

Lily：I agree with you. They worked and danced tirelessly and excitedly that night. Because of their support ，the opening ceremony was held very{#blank#}5{#/blank#} . 

Li Hua：That's right. {#blank#}6{#/blank#}at the opening ceremony were also wonderful. Many young people danced and sang for it. Sichuan Opera Face changing also appeared. 

Lily：I watched that. It's an{#blank#}7{#/blank#}opera with over hundreds of years' history. However，its history is {#blank#}8{#/blank#}longer than that of the Golden Sun Bird which had been put at the Jinsha museum. 

Lily：You mean the Golden Sun Bird. I know that. When the main torch was lit by torchbearers（火炬手），four golden birds and the sun also{#blank#}9{#/blank#}brightly. 

Li Hua：Because it symbolizes hope and brightness，we{#blank#}10{#/blank#}it as the logo（徽标） of the sports event. Moreover，I hope you can have a good trip in Chengdu!

Li Hua：Thanks!