Q: Frogs have a _-chambered heart.
Options:
- (A) alveoli
- (B) organ
- (C) ovaries
- (D) oxygen
- (E) edible
- (F) three
- (G) nektar
- (H) CO 2
Let's think step by step below.
Amphibians have a relatively complex circulatory system with a three-chambered heart. All frogs are amphibians. Frogs have a three-chambered heart.
Thus, the answer is (F).