2. Click Slide Show-Action Button-Custom Button, drag out three buttons in the slide, and set them as "No Action" in the action setting dialog box that appears. Select three buttons respectively, and select "Edit Text" in the right-click menu to add text to the play, pause and stop buttons respectively.

3. Select the speaker icon in the slide, click Slide Show-Custom Animation, double-click the box marked with the mouse to open the playback sound setting dialog box, select the timing tab, select the trigger object as the playback button in the drop-down box to the right of clicking the following object, and click OK.

4. Set the sound pause control to be controlled by the pause button. Continue to select the speaker icon, and click Add Effect-Sound Operation-Pause in the custom animation pane.

A pause control box appears below the Custom Animation panel. Double-click the control box to open the pause sound setting dialog box. Click the trigger button. In the drop-down box to the right of the effect when clicking the following objects, select the trigger object as the pause button, and then click OK.

5. Set the sound stop control to be controlled by the stop button. Click "Add Effect-Sound Operation-Stop" in the custom animation pane, and then set the trigger object to the "Stop" button as in step 4.

The final effect is as shown in the figure: