СРОЧНО! ДАЮ 30 БАЛЛОВ

Ex.1

1. harmful

2. conclusion

3. reactions

4. regularly

5. steadily

Ex.2

An earthquake is caused by a sudden slip on a fault. A fault is a fracture in the crust of the earth along which rocks on one side move relative to those on the other side. Stresses in the earth's outer layer push the sides of the fault together, pressure builds up and the rocks slip suddenly, releasing energy in waves that travel through the rock to cause the shaking that we feel during an earthquake.

Earthquakes tend to concentrate in narrow zones. There are 7 major crustal plates on earth, about 80 km (50 miles) thick, all in constant motion relative to one another. They move at between 10 and 130 mm (from less than one half to 5 inches) per year.

It is estimated that there are several million earthquakes in the world each year. Many of these earthquakes go undetected because they occur in remote areas or have very small magnitudes. On average, about 60 earthquakes per year are classified as significant, with 19 classified as major. A significant earthquake is one of magnitude 6.5 or higher or one of lesser magnitude that causes casualties or considerable damage. Major earthquakes have a magnitude larger than 7.0. The largest earthquake ever recorded occurred in Chile in 1960: it had a magnitude of 9.5.