Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.
--------
Question: What is the principle or uh when is the correlation occasionally positive?

Answer: When is the correlation occasionally positive?

Question: What helps or rather what are found in fossils?

Answer: What are found in fossils?

Question: When did the lower er uh last glacial end?

Answer:
When did the last glacial end?