1. Click Insert, Shape and Rectangle to insert a large rectangle and several small rectangles with the same size and length, aligned end to end.

2. In the upper right corner, set the filling color of the large rectangular box as white, and set the small rectangular box as shapeless outline.

3. Click Animation to set the erase animation effect for each small rectangle from left to right, and set the properties in the lower left corner from left.

4. After the start time of each animation is set to the previous animation, the animation time can be appropriately increased to achieve the effect of slowing down the progress bar.