Which of the following is the most important characteristic that biologists use to classify animals? where the animal lives
the animal's body structure
how long the animal lives
O population size of animal

The animal's body structure

Explanation:

Because all classes or animals have different body types.

Birds, class Avis, have feathers and lay eggs.

Salamanders, class amphibia, have smooth or slimy bodies.

Snakes, class reptilia, have scales and forked tongues.

answer; hydrologic cycle;

b) charles darwin i learned that last year!