between 1836 and 1994,san francisco had 11 earthquakes.earthquakes happen when rocks under the earth move. when they move a little. there is a small space. a line, between them. This is a "fault line"but the rocks to the right and left of the fault line can move further apart at any time-and that is an earthquake.there are two big fault lines in southem california near San Farancisco.
there are often small earthquakes in San Francisco.really big earthquakes happen there only once every 200 years. there was a big earthquakr in 1990.television pictures of buildings on fire in san francisco's marina district went around the world.people were afraid that tourists might stop coning. the whole city was not on fire,but on tv it looked like so.
麻烦高手们一定要速度翻译出来..T T
快点喔,马上就要..