When some plates of the earth move suddenly, an earthquake happens. Many earthquakes begin under the sea. Earthquakes may happen anywhere on the earth. They often happen near mountains. During an earthquake, the shakings make rocks rise suddenly and even crack open. Houses fall, people are killed and hurt, and sometimes whole villages or cities are destroyed. Can we do something to keep ourselves safe from earthquakes? Scientists have studied earthquakes and make maps that show "earthquake belts". In areas in these belts, it's possible for earthquakes to happen. In these areas we can build strong houses to fight against earthquakes. In the future, scientists will be able to predict exactly when and where an earthquake will happen. They can also tell people what to do with it. Which of the following often causes an earthquake to happen?
The rocks' cracking. The rock plates' sudden movement. The deep sea. Many mountains on the earth.