Given a sentence in Vietnamese, generate a new Vietnamese 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.

Anh là bình thường khi tìm thấy một cái phong bì trong hòm thư.
Rất có thể bạn sẽ bấm một phong bì trong bưu điện.