The Access keys used by this site are designated as follows
Alt+U：Upper area on the top side, containing the links to the services of this site.
Alt+C：Main content area, containing important or related information of this site.
Alt+F4：Close the window.
Shift+Tab：Back to previous item on this pages.
Powered tab key navigation order :
Starting from the top menu links , Carried to the left of the main menu links ,
Then moved to the center of Main Content Area , Finally moved Related Links area on the right.