Even with the greatest effort, our span of attention fluctuates.
即使付出最大的努力，我们的注意力也会波动。
英语演讲大全
But the other thing about Aadar is that he has a very short span, of attention span.
但关于 Aadar 的另一件事是他的注意力跨度非常短。
华研专八听力
This phenomenon reveals how our span of attention fluctuates, for the intensity of the ticking is actually constant.
这个现象揭示了我们的注意力广度是如何波动的，因为滴答声的强度实际上是恒定的。
英语百科
Attention span
Attention span is the amount of concentrated time one can spend on a task without becoming distracted. Most educators such as psychologists agree that the ability to focus attention on a task is crucial for the achievement of one's goals.