whenadv.什么时候；当 ... 时conj.然后；可是；当 ... 时pron.什么时候n.时间when in crisis在关键时刻When he come in他进来时When it comes to当涉及到； 当谈到When do you dine你们什么时候吃饭?When you talk.当你说话之际，When to use?n.[鱼]大口突鳃太阳鱼When I get there当我到达那里时When Directed by遵照…执行when all is saidadv.结果When You Are Old当你老了