Question

which choice provides the best summary of the passage? based on fossilized remains, two ancient shark species are thought to have lived in the ancient sea where mammoth park eventually formed. these newly discovered sharks might have been as big as twelve feet in length. fossilized teeth found in mammoth cave are in excellent condition because the cave, formed where an ancient sea used to exist, suffers little effect from outside environmental conditions. because of its ability to help preserve fossils over millions of years, mammoth cave is one of the most important sites in the world for paleontologists. research teams explore water - carved passageways that lead them to the discovery of new species. because deep sea caves are excellent environments for the preservation of fossilized remains, research teams often explore passages deep within mammoth cave. the fossils of teeth of two species of sharks were found in well - preserved condition.

Explanation:

The passage mainly discusses the discovery of well - preserved fossilized remains of ancient shark species in Mammoth Cave, which was formed where an ancient sea once existed. It emphasizes the preservation quality of fossils in the cave due to its environment.

Answer:

The best summary is that fossilized teeth found in Mammoth Cave are in excellent condition because the cave, formed where an ancient sea used to exist, suffers little effect from outside environmental conditions.