whenness时间性whenadv.什么时候；当 ... 时conj.然后；可是；当 ... 时pron.什么时候n.时间When will you leave Beijing?When your heart's shooting starsWhen to maintain your chain?When the work is unsuccessful.做人最失败的时候？When does the concert begin?When did your problem start?When shall we meet tomorrow?When it happened is immaterial.这事何时发生是无关紧要的。When are visiting hours over?When shall we have breakfast?