How do scientists know that some mountains were once at the bottom of an ocean?
Freshwater rivers flow to the ocean. Saltwater fish are found in some mountain streams. Dinosaur bones have been discovered in the mountains. Marine fossils have been found on the peaks of some mountains.
Question: How do scientists know that some mountains were once at the bottom of an ocean?
A. Freshwater rivers flow to the ocean.
B. Saltwater fish are found in some mountain streams.
C. Dinosaur bones have been discovered in the mountains.
D. Marine fossils have been found on the peaks of some mountains.
Answer: