Teacher: Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.
Teacher: Now, understand the problem? If you are still confused, see the following example:
Who did the Han Chinese want to help the Khitan no I mean the Mongols fight?
Solution: Who did the Han Chinese want to help the Mongols fight?
Reason: The input initially means Khitan and then changes to Mongols, hence this is correct.

Now, solve this instance: When rock formations are found on top of a fault that have not been cut, then formations no they must be older or younger than the fault?
Student:
When rock formations are found on top of a fault that have not been cut, then they must be older or younger than the fault?