Fact 1: Amphibians have a relatively complex circulatory system with a three-chambered heart. Fact 2: Frogs, toads and salamanders are amphibians. Given the two facts above, which animal has a circulatory system with a three-chambered heart?
Options are: 1). animals 2). Salamander 3). fur seals 4). mammals 5). alpacas 6). a fish 7). warm-blooded 8). barnacles
Answer:
2).