violently. during an earthquake, there is often a great noise first. then the earth shakes terribly, many houses fall down, railway tracks break and trains run off lines, a great many factories are destroyed, thousands of deaths are caused, and many more lose homes.… besides the great damage and deaths caused by the earthquake itself, other disasters such as fires often follow, more buildings destroyed and more deaths caused. it is well known of the dangers of a possible earthquake, and for centuries man has been making researches on earthquakes. more than 2000 years ago, for example, a chinese scientist named zhang heng invented a machine which could detect earthquakes, and this machine is still used by scientists today to detect and measure the strength of earthquakes. now we know much more about earthquakes and why they happen, but we still cannot tell exactly when and where an earthquake will happen, and cannot stop it from happening. so earthquakes are among the worst disasters in the world.
