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.

You are likely to bump trees in a forest .
You are likely to steal trees in a forest .

You would bounce out of a window because of a terrorist attack .
You would say out of a window because of a terrorist attack .

Trees are partly made of material .

Trees are partly made of wire .