20. Three common characteristics of adult vertebrates are

a. skull, notochord, and complex organ system
b. backbone, segmentation, and open circulatory system
c. two pairs of jointed appendages, cephalization, and internal skeleton
d. hydrostatic skeleton, bilateral symmetry, and true coelom
A?

-MC

2 answers

I hope when you are an adult, you do not have a notochord.

Not a.
D?

-MC