TASK DEFINITION: Given a sentence, generate a new sentence by performing small changes on the sentence. Here, make sure that the changes are semantically related and syntactically similar to the input. And the generated sentence should have high commonsense plausibility, that is to have reasonable probability of it being true.
PROBLEM: People go to the cinema to watch a film.

SOLUTION: People go to the cinema to watch a spectacle .

PROBLEM: You are likely to find a steel pen in a writer's pocket.

SOLUTION: You are likely to find a steel pen in a bartender 's pocket .

PROBLEM: A grenade can destroy the trigger of a gun .

SOLUTION:
A calculator can pull the body of a gun .