The keju examination system ran from the Sui and Tang until its abolition in 1905, and the physical conditions are worth stating plainly because they are usually omitted. Candidates for the provincial examination were sealed for three days and two nights in individual brick cells roughly one metre by one and a half, containing two removable boards — one to sit on, one to write on, and at night placed together as a bed. Food was brought in; the cells were not left. Candidates who died during the session were not carried out through the gates, which were sealed, but passed over the wall. The Ming and Qing required essays in the eight-legged form, a rigidly structured argument on a set passage from the Four Books answered in Zhu Xi's interpretation. Success rates at the highest level were on the order of one in several thousand, and men sat repeatedly into their sixties and seventies. Its modern descendants — the gaokao in China, the suneung in Korea, where flights are grounded during the listening section — retain the defining feature: one examination, a few days, and a life sorted by the result.