This website is based on the design principle of accessibility and uses keyboard shortcuts to strengthen the browsing convenience Layout is divided in 4 areas：
1. the main menu zone at the top、2. the content zone at the center、3. the menu zone on the left side、4. the related information zone at the bottom.
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.
Alt+L：Links on the Left area.
Alt+Z：Bottom Link area.
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.