attention deficit hyperactivity disorder

例句：

1. 1.He has ADHD and struggles with attention spans.
   他有注意力缺陷多动障碍，注意力跨度小。
2. 2. The teacher noticed that the student had difficulty focusing on the lesson.
   老师注意到学生很难集中注意力在课堂上。
3. 3.The child's hyperactivity made it hard for him to sit still during class.
   孩子的过度活跃使他在课堂上很难保持安静。