This website is based on the design principle of accessibility and uses keyboard shortcuts to strengthen the browsing convenience Layout is divided in 3 areas：
1. main menu zone at the top, 2. the menu zone on the left side, 3.the content zone at the center.
The following keys are set as the Access keys ( or speed keys) of this website.：
Alt+U：The top of the main menu links area, mainly home, sitemap, language.
Alt+L：Menu links on the Left area.
Alt+C：Main content area shows the content of each page.
Alt+F：Foot area of this website, include main url navigation.