Sal drew a diagram to compare vertebrates and invertebrates.
((picture at the bottom))
choices:

are eukaryotic
have an outer skeleton
are heterotrophs
have a backbone

D, Have A Backbone

Explanation:

Animals that have a backbone are called vertebrates. The backbone is is a column of bones that supports the body, and also protects the spinal cord. The back is made up of many separate bones, called vertebrae. The backbone is part of a vertebrate's supportive internal skeleton.

zfoods? ok, pressure is used to keep the heat inside and to keep the food perfect.

2b2t

explanation:

2b2t