National examinations to select students for higher education (and positions of leadership) were an important part of China's culture, and, traditionally, entrance to a higher education institution is considered prestigious. Although the examination system for admission to colleges and universities has undergone many changes since the Cultural Revolution, it remains the basis for recruiting academically able students. When higher education institutions were reopened in the early 1970s, candidates for entrance examinations had to be senior-middle-school graduates or the equivalent, generally below twenty-six years of age. Work experience requirements were eliminated, but workers and staff members needed permission from their enterprises to take the examinations.