Assertion: rift valley | /r/HasProperty | rich source of fossils
Facets:
Source sentences:
text: The Rift Valley has been a rich source of fossils that allow study of human evolution.
text: The Rift Valley in East Africa has been a rich source of hominid fossils that allow the study of human evolution.
text: The Rift Valley has been a rich source of fossils that allow study of human evolution, especially in an area known as Piedmont.
text: The Rift Valley in East Africa has been a rich source of hominid fossils that allow the study of human evolution.