whenadv.什么时候；当 ... 时conj.然后；可是；当 ... 时pron.什么时候n.时间When do you dine?你们什么时候吃饭?When can I board?三开模When can I start?三节上蜡软木塞, 香槟酒瓶塞When i speak with sob当我抽泣着诉说when doctors disagree当大学者们意见分歧时When you turn left.当你转身离开.when occasion demands遇必要时When are you off?三叠式when a vacancy occurs有空额的时候When Something Is out当客人点菜没有时