Some scientists contend that many species of dinosaur had a metabolism more like a warm-blooded mammalâ€™s than a cold-blooded reptileâ€™s.
A. that many species of dinosaur had a metabolism more like
B. that the metabolism of many dinosaur species were more like
C. that the metabolisms of many species of dinosaurs were more like those of
D. there were many species of dinosaurs that had metabolisms more like those of
E. there were many dinosaur species that had a metabolism more like that of
So I think it's either A or B because the possesives account for the missing 'metabolism'.....I would go with A....
with B....'metabolism were' is bad.
having said that...i would go with
"Do or do not, there is no try."