TASK DEFINITION: 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.
PROBLEM: You 've certainly learnt a lesson , the submarine will be very interested in you . "

SOLUTION: Changed

PROBLEM: " We need to do our human testing , don 't want to have any more deliveries by waiting for vaccination of a test subject .

SOLUTION: Changed

PROBLEM: It was an old heavy building , built of devastation and stone , that looked like it had grown slowly up from the forest floor .

SOLUTION:
Changed