attention span
noun [ C ] uk/əˈten.ʃən ˌspæn/ us/əˈten.ʃən ˌspæn/
注意广度（指将心思和兴趣集中于某一事物的时间长度）
the length of time that someone can keep their thoughts and interest fixed on something
Young children have quite short attention spans. 小孩子的注意广度很短。