question... What has a relatively complex circulatory system with a three-chambered heart?
Options:
- (A) frogs
- (B) a fish
- (C) salmon
- (D) alpacas
- (E) Man
- (F) Birds
- (G) sharks
- (H) pan
answer... Amphibians have a relatively complex circulatory system with a three-chambered heart. All frogs are amphibians. Frogs have a relatively complex circulatory system with a three-chambered heart.
The answer is (A)

question... What element can be stored in limestone for millions of years?
Options:
- (A) oxygen
- (B) Energy
- (C) matter
- (D) carbon
- (E) sodium
- (F) helium
- (G) rock salt
- (H) heat
answer... Carbon may be stored in sedimentary rock for millions of years. Limestone is a type of sedimentary rock. Carbon may be stored in limestone for millions of years.
The answer is (D)

question... What do animals try do in winter?
Options:
- (A) shed fur
- (B) expand
- (C) ligt
- (D) rest
- (E) adapt
- (F) use an adapter
- (G) survive
- (H) die
answer...
Animals adapt to cold temperatures. And in winter it s very cold. In winter animals can adapt.
The answer is (E)