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: Two children, one wearing purple, the other black, ride a single bike on the pavement. Sentence 2: Two children ride the same bike.
Two adults ride a double seater bike.

Sentence 1: A waiter dressed in business attire holds up a pan filled with meat laden with sauce and garnished with lemon. Sentence 2: A waiter is holding food.
The man is taking a nap in between shifts.

Sentence 1: A black and brown dog is running with a tennis ball in its mouth. Sentence 2: A dog with a tennis ball.

A dog with a stick in his mouth.