moves, they move with it.

　　Earthquakes can also break up gas or oil pipes. This can cause fires to break out, which can do as much damage as the earthquake itself.

　　Another effect of earthquakes is tsunamis (海啸). These are huge waves created by earthquakes beneath the sea. They can be many metres high and cause great damage to coastal towns and cities.

　　China, Japan, Russia and the USA have the highest occurrence (发生) of earthquakes in the world.

　　Knowing about 71.__________ 　　Two serious earthquakes in 72.__________ 　　An earthquake and 73.__________ fires destroyed both Tokyo and Yokohama in Sept. 1923. 　　 　　In 1556, a very serious earthquake 74._________ in China's Shanxi Province. 　　The way to 75._________ an earthquake's strength 　　People can measure an earthquake's strength on the Richter scale of one to ten, 76._________ in 1935 in the USA. If an earthquake measures five or more, it's usually serious. 　　The 77._______ of earthquakes 　　As the plates, which form the earth's 78._______, move, they sometimes crash against each other, causing the crust to quake. 　　Some 79._____ of earthquakes 　　If earthquakes break up gas or oil pipes, 80._______ will happen, which can do as much damage as the earthquake itself. 　　 　　Tsunami is another effect of earthquakes.