In this task, you are given a sentence. You must judge whether a single noun or verb has been replaced with another word with the same part of speech. The inversion would result in the sentence sounding unnatural, So unnatural sentences will be considered changed. Label the instances as "Original" or "Changed" based on your judgment.

[Q]: Raptor winked at Gina as she flashed her ID to the buggy and he led her through .
[A]: Changed


[Q]: They were close to the surface of the tendon , and getting closer .
[A]: Changed


[Q]: How did he just happen to stumble on board a military base and meet somebody who later on just happened to become part of a programming experiment ?
[A]:
Original