Прочитайте следующей текст. найдите в каждом предложении группу «подлежащее-сказуемое». переведите предложения с глаголом-сказуемым в страдательном залоге. the book planet earth, an encyclopedia of geology is often referred to because it gives much information on the geological history of the earth,
the rocks of earth, the processes which occur in the earth, etc. for example, sedimentary rocks form a small proportion by volume of the rocks of the earth's crust. they are formed from sediments, accumulations of solid material. the oldest sedimentary rocks were known some 3,500 million years ago.
the processes which lead to the formation of sedimentary rocks are going on around us and different sediments are being deposited and may later be changed into rocks. most sedimentary rocks have been classified according to their grains size. great attention is also paid to the rocks of the oceans
because they are less studied.