Scientists specializing in the analysis of growth-rings in trees that grew in all parts of the U. S. have arrived at some important 
(Scientists; specializing; in the analysis of growth-rings in trees) (trees; grew; L:in all parts of the U. S.) (Scientists specializing in the analysis of growth-rings in trees; have arrived; at some important)
Scientists trees Scientists specializing in the analysis of growth-rings in trees
specializing grew have arrived
in the analysis of growth-rings in trees
L:in all parts of the U. S.
at some important