TASK DEFINITION: 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.
PROBLEM: Sentence 1: A crowd surrounds a grounded hot air balloon. Sentence 2: Crowd watching someone fly away

SOLUTION: Crowd gathering

PROBLEM: Sentence 1: Exhausted looking men and women are finishing up a marathon. Sentence 2: Exhausted looking men and women are being chased by a killer

SOLUTION: Exhausted looking men and women are running

PROBLEM: Sentence 1: Security guard at a art museum. Sentence 2: Security guard apprehending a subject at a museum.

SOLUTION:
Security guard at a museum.