Earthquake are common: thousands of them happen each day. But most are too weak to feel. During a 1 earthquake, there is often a great noise first. Then the earth 2 terribly and many houses fall down. Railway tracks break and trains go 3 lines; a great many factories are destroyed; thousands of deaths are caused, and many more lose homes. Besides the great damage and deaths caused by the earthquake 4, other accidents such as fires often 5.

    More buildings are destroyed and more deaths caused.

    It is well-known of the dangers of an earthquake, 6 for centuries man has been making researches on earthquakes. More than 2000 years ago, 7, a Chinese scientist named Zhang Heng invented a machine which could 8 from which direction the seismic waves（地震波）had come, and this machine is still used by scientists today. Now we know much more about earthquake and    9 they happen, but we still can't  10 exactly when and where an earthquake will happen, and can't stop it from happening.

    Many scientists say that the world is getting hotter and hotter. If they are right, the ice at the North and South Pole will melt eventually. If this happens, the sea will 1 and may cover most or all of Singapore. This will force everybody to move to a 2 country.

    We know that the sun 3 the earth. The heat from the sun hits the ground, and some of it goes back into the sky. However, factories and cars 4 a lot of carbon dioxide (二氧化碳). When the gas rises into the sky, the heat from the sun can come through them but the heat from the ground cannot. It 5 near us in the sky and makes the 6 hotter and hotter every year.

    Scientists 7 this the “greenhouse effect” because a greenhouse is a small glass building which is hot inside. It is used for     8 plants in cool countries. Many countries are 9 about the “greenhouse effect”. They are trying to stop factories and cars from sending  10 gases into the sky. Scientists are not sure when the world will get much hotter. Some people say that the “greenhouse effect" has started already and has begun to affect (影响) the world's weather.

    There was a small village near the mountain. There were a lot of trees in the mountain. People in the 1always got something from the mountain, such as animals and trees. When they wanted to 2a house, they cut down the trees. And they also killed the animals for 3. Trees were very 4in their daily life. They made tables, chairs 5beds by cutting down the trees. In addition, when they 6meals, they still used some trees for wood. However, they only cut down trees but 7planted new trees. So the trees were fewer and fewer and the animals were becoming 8as well.

    One summer, it rained 9in the village. The rain lasted for about a week. The soil and the stones on the mountain fell down and soon 10the whole village. They finally realized they couldn't only cut down trees but also needed to protect them.

    When talking about inventors, who do you first think of? Forget Thomas Edison. Meet the teenage 1 at the 24th Jiangsu Adolescents Science &. Technology Innovation Contest(江苏青少年科技创新大赛).

    Wang Xingyu, from Kunshan No. 2 Middle School, invented "a 2 line" in the zebra crossing. Wang often saw people running through

the red 3 , so he thought of an idea,

    "I 4 a spray tube(喷管) in the zebra crossing. When the light is red and 5 crosses, it sprays water. If the light is 6, it will not work," said Wang.

    But does it 7 water? "There's a water channel(槽) on the ground, so the water will be collected and 8 again," he said. Zong Hangchen, from Nantong Special Education Middle School, also got his invention idea from daily experience.

    Zong's 9 could only feel a little light. When he walked on the sidewalk for the blind, he often came across obstacles(障碍物). Once he 10 hurt his nose.

    11 help himself and the blind, Zong made something that has radar(雷达) and a loudspeaker. Users tie radar onto their knees and 12 the loudspeaker around their necks. When they meet obstacles, the radar will see them and the loudspeaker will make a 13 to tell the users.

    Chen Huijuan, an official from Jiangsu Association for Science and Technology, was 14 at these inventions.

    15 some ideas are simple, the creations are very good," she said. "Get inspiration( 灵感) from small things in life and you can be an, inventor, too.