we can't stop an earthquake(地震), but we can do things to make sure they don't destroy(毁坏) whole cities. first, it is not a  idea to build houses along lines where the  of the earth's plates(板块) join together. Second, if you think there  be an earthquake, it is better to build houses on rocks , not on  . Third, you must make the houses as  as possible. Weak buildings will fall down in an earthquake, but strong ones may  Scientists are  that one day an even bigger earthquake will hit the part around San Francisco(旧金山) . They call it " the big one ". However, people today are still building more  .The population in and around San Francisco is now ten  more than it was in 1906.This means that  there is another earthquake, a great many houses and buildings will be destroyed.