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 it is safe to come out. The teacher should, at the same time, go immediately to the teacher's desk, get underneath it and stay there till the danger is over. Students must not argue with the teacher or question instructions.As soon as the tremors (震动) stop, all students should walk towards the exit and go straight to the school playground or any open space such as a square or a park. They must wait there until the teacher tells them it is safe to go.●At homeIf you are at home when the earthquake occurs, get immediately under the table in the living room or kitchen. Choose the biggest and strongest table you can find. You must not go anywhere near the window and don't go out onto the balcony (阳台). Once the tremors have stopped, you can come out from under the table but you must leave the building straight away. You should walk down the stairs and should not use the lift — t...
