The answer to your question would be that the sentence that contains an unnecessary shift in verb tense is the following one: Lee noticed a problem and alerts a teacher.
Explanation:
In the sentence above, the first verb phrase is in the past simple tense and the second one is in the present simple tense. The fact is that the verb tense expresses a sense of time in a sentence, paragraph, or paper. The writer should establish the time perspective in the opening sentence and maintain that tense consistently throughout his or her work. As I've said, the time reference is not maintained within the sentence in question. Consequently, this may cause distractions to the reader and a break in coherence. Therefore, the sentence should be as follows: Lee noticed a problem and alerted a teacher.
The sentence that contains an unnecessary shift in verb tense is the second one - Lee noticed a problem and alerts a teacher. It should be <em>alerted, </em>which is the past tense as the first verb <em>noticed.</em>
For me, I enjoyed reconnecting with myself. Juggling school and just life in general was such a stress. Having to wake up so early and go to class to class was hard. But now, I'm so happy. I picked up art again and it made me forget.
The sentence presented above is an example of a complex sentence based on its structure. A complex sentence contains an independent clause and a dependent one. In the given the independent clause is the man was already listening to his new iPod and the dependent clause is ready to go out for his daily jog around Central Park.