1） but， but on the contrary， but on the other hand， but then；2） by contrast， in contrast， in contrast with/to， as a contrast to， as opposed to；3）by contraries， on the contrary， to the contrary， contrary to （A）， opposite to， in opposition to；4） whereas， while， while on the other hand， while on the whole， yet， however；5） （as） compared with/to， by comparison， in comparison with， by comparison to. 6） First……， Next……， Last……；7） In the first/early/initial/infant period/stage/phase（或In its infancy） ……， In the second/middle/adult/ripe period/stage/phase……， In the third/last/closing/later/concluding period……；8） One step （way/course/approach/secret/trick）……， Another step……， Still another step……；9） The first measure/step/move……， Next to it comes……， And the last/final/the most important measure……；10） The direct experience/lesson/factor/way（或One lesson）……The indirect experience/lesson/factor/way（或The other lesson）……