How to add comments about PPT so that the audience can't see it?

1. First, open powerpoint 20 10 in your computer and click Slide Show.

2. Then, in Open Options, click Set up Slide Show.

3. Then, in the window that opens, click the check box to use the presenter view, as shown in the figure below, and click OK.

4. Finally, in the opened page, as shown in the figure below, click to play from the beginning.