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 cotton be planted?When did the accident occur?When the Death whispering low.当死神在耳旁低语，When will the criticism end?When the horizon darkens most.而当地平线变得更暗时，When moisture content below F.当含水率低于F.When is the canteen closing?When did the vomiting start?When do the fireworks start?When does the program start?