In a comparison of birds and mammals, the condition of having four limbs is
a. a shared ancestral character.
b. a shared derived character.
c. a character useful for distinguishing birds from mammals.
d. an example of analogy rather than homology

a. A shared ancestral character.

Explanation:

A shared ancestral character is the character or feature that two lineages of same or distinct species have in common derived from a common ancester. The four limbs in birds and mammals is the example of this.

rising temperatures because when water vapor in the air is cooled, it condenses. it turns back into a liquid and attaches to dust particles in the air. these very small water droplets group together to form clouds

what in the weirdo : o