Submitted by admin on Fri, 04/18/2014 - 15:48
definition:
An animal of a large group distinguished by the possession of a backbone or spinal column, including mammals, birds, reptiles, amphibians, and fishes
sentence:
For that reason the earliest terrestrial vertebrates did not come equipped with an occiput, as we understand the term.
difficulty:
medium
toefl frequency:
3
toefl classification: