narrowing of attention-span

例句：

1. 1.The student's ability to concentrate is narrowing as the deadline approaches.
   随着截止日期的临近，这位学生的注意力集中能力正在减弱。
2. 2. As the novel progresses, the protagonist's attention span is noticeably reduced.
   随着小说的发展，主角的注意力跨度明显减小。
3. 3. The teacher noticed that students were becoming increasingly distracted during class discussions.
   老师注意到学生们在课堂讨论时越来越分心。