Условие:
1. Scientists think the history of geology to go back about 4.6 billion years.
2. The ancient Romans believed the God named Vulkan to be a skillful craftsman.
3. Where there is shale there is likely to be oil.
4. For many years scientists assumed the basic arrangements of oceans and continents to be stable and permanent.
5. The geologists found out the earth's outer shell to be not one solid piece of rock, but to be composed of a number of large, moving slabs of rock, called plates.

