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: You are likely to bump trees in a forest .

SOLUTION: You are likely to steal trees in a forest .

PROBLEM: You would invest kind or energy because you appear to make more money .

SOLUTION: You would invest money or care because you want to make more money .

PROBLEM: You can study old artifacts to learn about the past .

SOLUTION:
You can study lunar artifacts to learn about the past .