In this task, you're given a pair of sentences, sentence 1 and sentence 2, that agree with each other. Your job is to alter sentence 2 so that the pair 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 teenage boy is holding his skateboard. Sentence 2: A boy is posing with a skateboard.
A boy is posing with a bicycle.

Sentence 1: Man wearing hat and glasses working on a bicycle. Sentence 2: A man is working on his bike.
A person is riding his bicycle on the street.

Sentence 1: Two brown dogs run across a large snowy yard. Sentence 2: two dogs are running in the yard

two dogs are cuddled up sleeping