Question

homologous structures like bones help to show that vertebrates
share a common ancestry
that limbs always serve the same function in all animals
they do not share any structures.
that structures are created from scratch in different animals
rewatch
submit

Explanation:

Homologous structures are defined as structures in different species that are similar because they were inherited from a common ancestor. So the correct statement about homologous structures (like bones in vertebrates) is that they share a common ancestry. The other options are incorrect: homologous structures can have different functions (so "That limbs always serve the same function in all animals" is wrong), they do share structural similarities due to common ancestry (so "They do not share any structures" is wrong), and they are not created from scratch (they are modified from ancestral structures, so "That structures are created from scratch in different animals" is wrong).

Answer:

Share a common ancestry