a. A shared ancestral character.
Explanation:
The condition of birds and mammals having four limbs is a shared ancestral character because the structure of the limbs are similar in both the cases.
The forelimbs of the bird are modified into wings to aid flying.The hind limbs are modified into feel and claws.
These are homologous structures to the hands and feet in mammals.
That means they have a common origin, and hence are shared ancestral character.
Answer:
They are made of gases.
They contain iron in their cores.
They make energy through fusion.
T~T
sowwy I can't, I can't see them very well but just guess and google the ones you can, good luck!!