title: How to edit the label of a chart in Excel?
body: <p>As shown in the figure below, the horizontal axis is automatically produced by the Excel and labeled as 1,2,...,n. What I wanna to do is to change these labels into such a form as case A, case B,..., etc. </p>
  
  <p>I tried to edit the chart, but all failed.</p>
  
  <p><img src="https://i.stack.imgur.com/ARyDt.png" alt="enter image description here"></p>