2. Click File-Document Properties-Security.

3. Select No Security Settings in the Security Method list, and then click the OK button twice.

PDF is a unique cross-platform file format developed by Adobe. Is a foreign abbreviation of portable document format, and it is also an extension of this format.

It can package all information such as text, format, font, color, resolution, link, graphic image, sound and dynamic image of a document in a special integrated file. It has a high technical starting point and full functions.

Much stronger than the existing popular text format; There is also a well-known and powerful Adobe company to promote it, and now it has become the undisputed industry standard for a new generation of electronic texts.