Определите основную идею текста
Last century gave rise to many theories about the mountain origin and evolution.
Most textbooks on Geology of the 20th century dealt with the mountain origin because it is the most important problem of science.
The 20th century is the century of discoveries in all fields of science.
Careful study of the textbooks on Geology allows to see the evolution of the theory of the mountain origin and the final conclusion the scientists of the 20th century came to.