Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.

Example input: Who did the Han Chinese want to help the Khitan no I mean the Mongols fight?
Example output: Who did the Han Chinese want to help the Mongols fight?
Example explanation: The input initially means Khitan and then changes to Mongols, hence this is correct.
Q: How did or no make that when did geologists begin comparing fossils to each other?
A:
When did geologists beginning comparing fossils to each other?