LaTex Learning Records - Page Setup

  Operating system: Ubuntu 14.04LTS; tool: TeXstudio; in addition, I also installed the complete texlive (sudo apt-get install texlive-full, it is relatively large, you can install the part as appropriate).
  The default page setting of TeXstudio is not what I need. Generally, I like to set the page to A4 paper. The method is as follows:

\usepackage{geometry}
\geometry{a4paper, scale=0.8}  % 设置为A4纸，边距0.8