This website is based on the design principle of accessibility and uses keyboard shortcuts to strengthen the browsing convenience Layout is divided in 2 areas：
1. the main menu zone at the top
2. the content zone at the center
The following keys are set as the Access keys ( or speed keys) of this website.：
Alt+U：Upper block, containing the links to the services of this site, search box, font size setting and versions of this site.
Alt+C：Main content area shows the content of each page.
If your browser is Firefox, Press Shift + Alt + Key to jump. For example, press "Shift + Alt + C" to jump to the center of the page.