回複：請問, 哪兒可以"真正地"免費下載把文件掃描成PDF文檔的軟件?

I don't quite understand what do you mean be 把文件掃描成PDF文檔. Do you mean scan a paper document, then convert it to a PDF file? If you want to convert a word (excel or powerpoint) file to a PDF file, and don't use acrobat, you have two ways:
1. Install OpenOffice, it is free. Openoffice can open word, excel, powerpoint files if the files don't have very complex format. Once opened in OpenOffice, just click the PDF icon, your file is converted to a pdf file. It is so simple.
2. Print to a file to generate a post file, then convert the post file to a pdf file in ghost. I haven't use ghsot for long time, so I am not very sure. But I believe it can do that.