状语从句的九种常见类型1， 时间状语从句a：引导词有：when ,while ,as ,till ,until ,after等b：注意as，when，while的区别。As强调时间上的“一先一后”，“同一时间”，或“随着”之义，例如：As the time went on ，the weather got worse。when则强调某个特定的时间；例如：when he was eating his breakfast，he heard the door bell ring。while表示的时间不是一点，而是一段时间内。例如：Strike while the iron is hot。2， 原因状语从句a：引导词有because，since， as ，for the reason that，in that 等 b：其中because表示原因的语气最重。例如：Because they lived on the edge of the Persian Empire ,they were ruled by the king of the Persia .as和since所
