说明：  PDF文档密码清除软件：在转换成pdf文件是，可以设置文档禁止拷贝，打印，打开时需要密码等功能，此软件可以清楚pdf设置的所有密码。非常适用。
(PDF documents password removal software: in the pdf document is converted, you can set the document to prohibit copying, printing, open password, etc. need to function, this software can set up all the password pdf. Very applicable.)