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 Accesskeys used by this site are designatedas follow：
- Alt+U (IE), Alt+Shift+U (Firefox): Upper block, containing links to the major sections and services of this site.
- Alt+C (IE), Alt+Shift+C (Firefox): Center block, providing the principal information of the page.