Read the following paragraph and underline the topic sentences.
Jack shouldn’t have taken the gymnastics course. In September, he fell off the uneven bars and got a concussion. A month later he sprained his ankle, after a bad landing off the balance beam. In January, he broke his thumb when he caught it on the bar of the pommel horse. He also broke the support beam in the basement of his parent's home,showing them his skills when he was home for the December holidays. His academic luck was no better than his physical luck: he failed the mid-semester exam in November and the final exam in January in his gymnastics course. The result of his bad luck was that he failed to graduate in May, due to the lack of two hours of physical education credit.