Attention "is a mental state that selectively points to and focuses on a certain object or activity. " Attention can be divided into "intentional attention" and "unintentional attention" according to whether it is generated and maintained for conscious intention and effort. According to the above definitions, which of the following is the following description of the status of the students as "intentional attention"? ['Zhang rushed to the classroom two minutes after the bell rang, and he shouted "Report" at the door, so that the attention of the students turned to Zhang.', "When talking about the Cultural Revolution, Teacher Li suddenly took an enlarged old photo from the podium, and the classmates' eyes were immediately attracted.", 'Professor C. Huang made a continuous report on the stage for nearly an hour and a half, and was still tired. Sudden power failure, the microphone was silent, and the thousands of students who had originally talked quietly in the audience calmed down.', 'Mr. Liu said, "The scope of this exam will be announced below. ".']