Unit 4EarthquakeWarming upfireNatural Disastersfloodtyphoonsnow slide (雪崩雪崩)volcano (火山火山)mudflowsandstormTsunami (海啸）海啸）earthquake On May 12th, 2008 14:28 A big earthquake happened in WenChuan Sichuan !Many people believe that “it is always calm before a storm,” look carefully at the two photos. Now, imagine there has been a big earthquake. Describe what might happen to the objects in the photos. TangshanTangshan, HebeiJuly 28th, 1976San Francisco1906年年, 旧金山旧金山地震后街景地震后街景1906年年, 地震后旧金山市地震后旧金山市区被扭曲的电车轨道区被扭曲的电车轨道 Tall buildings were destroyed.Roads were cracked.People were injured.The city was in ruins.Do you know why an earthquake happens?San FranciscoPacific plateAmerican plateEurasian plate India plateAfrican plateAntarctic plateParagraph 4Pacific plate NorthSouthWestEastAmerican plateEarthquake HappensHomework Surf the Internet to find more information about the Tang Shan earthquake and the San Francisco earthquake.