Unit 4 Earthquakes EarthquakeHow does an earthquake start
What makes an earthquake happen
The rock of the earth's crust (地壳) may have a fault, a kind of break in the surface
The blocks which make up the earth move, and sometimes this may cause the sides of the fault to move up and down or lengthways (纵向地) against each other
When one piece of rock starts to rub on another with great force, a lot of energy is used
This energy is changed into vibrations (振动) and it is these vibrations that we feel as an earthquake
The vibrations can travel thousands of kilometres and so an earthquake in Turkey may be felt in Greece
What should we do during an earthquake
●At schoolAs soon as the earthquake starts, students should get under the desks immediately and wait until the teacher tells them i