By studying fossils, scientists have been able to piece together some of the important pages in the history of the Earth and its people.
(scientists; have been; able to piece together some of the important pages in the history of the Earth and its people) (scientists; to piece; together; some of the important pages in the history of the Earth and its people)
scientists scientists
have been to piece
able to piece together some of the important pages in the history of the Earth and its people
together some of the important pages in the history of the Earth and its people