Question

Which characteristic do birds and mammals have in common? question 17 options: both have fur or hair. both are endothermic vertebrates. both have three-chambered heart. both are vertebrates that produce milk.

Answer 1

I think the answer is both are endothermic vertebrates.

Endothermic vertebrates are ones which can produce their own heat and have a spine (backbone).

so.. the answer is endothermic vertebrates.

Hope it helps.