what have more complex nervous systems
animals without a backbone the wearing away of rock h2o barks and snarls plants density Veins and arteries. remains of prehistoric life
A B C D E F G H
Invertebrates are animals without a backbone.
most animals without a backbone have a complex nervous system
what have more complex nervous systems (A) animals without a backbone (B) the wearing away of rock (C) h2o (D) barks and snarls (E) plants (F) density (G) Veins and arteries. (H) remains of prehistoric life