In this task, you're given a pair of sentences, sentence 1 and sentence 2, that neither agree with nor contradict each other. Your job is to alter sentence 2 so that the pair clearly contradict each other. Generated sentences must be short, with less than 15 words. New information can be introduced. Avoid using pronouns to confuse the subject of the sentence.

Sentence 1: A boy rides down a slide into a small backyard pool. Sentence 2: A boy goes down a slide on his stomach.
The men are changing the stone.

Sentence 1: A person in a black jacket is grabbing a boy's shoulder to stop him from backing into the road while a silver Mini is driving by. Sentence 2: A father is grabbing his son's shoulder.
A silver mini is on the road.

Sentence 1: At a naval yard, a man in a white Navy officer's uniform is standing by two older men having a discussion. Sentence 2: A Navy officer listens to two men discuss important policy together.

A Navy officer is watching a conversation.