Answer:
fossil record of dinosaurs
Explanation:
geologists used fossils, meteor rocks, and rocks to figure out that earth was 4.6 billion years old
C.is correct...............
Answer:
The decreased atmospheric pressure and low levels of oxygen can have very dangerous effects on a climber's body. Even though there is less oxygen available to the climbers, their bodies can learn to compensate. The human body survives by breathing air into lungs.