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: Man in a one shirt popping wheelies in the air on a red bicycle in a path lined by grass. Sentence 2: A man is riding a bike in a trick competition.
A man is riding a bike.

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: Two brown dogs biting each other on sand. Sentence 2: The dogs are fighting over a bone.

The two dogs are outside.