1、 The earth is a little blue planet.There always happen some disasters(灾祸灾祸)What natural disasters do you know?Look carefully at the two pictures.Describe what you see in the pictures.But unfortunately,in 1906 a big earthquake happened in San Francisco.Whats worse,a bigger earthquake happened in Tang
2、shan in 1976 in China.Imagine what might have happened to all the things in the photos.1.What damages does the earthquake caused?Houses fell down.Bricks covered the ground.Brick buildings were destroyed.Factories,hospitals,schools,and the other buildings were gone and lost.Roads got huge cracks.Many
3、 buses were caught in them.A huge crack might have cut across houses,roads and canals.Steam burst from holes or wells in the ground.Water pipes cracked and burst,so the water supply was cut off.The smoke of fires could be seen.The electricity lines were destroyed.The electricity supply was also cut
4、off.Bridges and dams fell down or were not safe for travelling.Railway tracks were useless pieces of steel.The transportation was delayed.Many people died and were injured.Families were killed and many children were left without parents.The survivors became homeless.Workers built shelters for surviv
5、ors whose homes had been destroyed.shelters for survivors.In a few terrible seconds,a large city lay in ruins.Everything was destroyed.It seemed that the world was at an end.2.What do you think may happen before an earthquake?People can see bright lights in the sky.The sound of planes can be heard o
6、utside even when no planes are in the sky.Chickens,pigs,dogs,cows and snakes are nervous.Mice run out of the fields.Fish jump out of bowls and ponds.The well walls have deep cracks in them.The water in the well rises and falls.A smelly gas comes out of the cracks3.Why do earthquakes happen?Pacific p
7、lateAmerican plateEurasian plate Indian plateAfrican plateAntarctic plate北北American PlateAmerican PlatePacific plate American plateSan Francisco Sometimes these two plates stop and do not move for years.Then Suddenly,they jump and an earthquake is felt.As a result of the movement of these plates,west America near the sea has always been a bad place for earthquakes.When the 1906 earthquake happened,the Pacific plate jumped 5-6 meters to the north.ContinentOceanic plateThank you!
