Final answer:
The paragraph lacks sentence variety because every sentence begins with the subject 'Cory', making it monotonous.
Step-by-step explanation:
The paragraph in question lacks sentence variety because each sentence begins with the subject. This repetitive structure can make the writing seem monotonous. To improve sentence variety, one could start some sentences with a prepositional phrase, an adverb, or a dependent clause. For instance, instead of starting every sentence with 'Cory,' one could rephrase a sentence to begin differently: 'Every day after school, Cory attended the rehearsal.' By varying the beginnings of sentences and the structure, the writing will become more engaging and less predictable.