Amphibians have a relatively complex circulatory system with a three-chambered heart.
Frogs, toads and salamanders are amphibians.
Salamanders have a relatively complex circulatory system with a three-chambered heart.
Which animal has a circulatory system with a three-chambered heart?
1: animals
2: Salamander
3: fur seals
4: mammals
5: alpacas
6: a fish
7: warm-blooded
8: barnacles