EASY 13 POINTS, PLEASE ANSWER

What is the problem with the following sentence: cameron, who has an extreme and unreasonable suspicion of other people and their motives, suffers from paranoia which is a psychological disorder characterized by delusions of persecution or grandeur, was absolutely sure that someone was following him even though he was absolutely alone and hadn't seen a car for miles and miles.

It was a bitter cold saturday morning ,the young track star dressed for his daily five mile run

Dogs make wonderful pets because they keep us happy and healthy, the topic sentence is "dogs make wonderful pets". can someone me write a unrelated sentences to the topic and can be eliminated. need asap