表层进first，firstly，to start with， to begin with，second，secondly，third， thirdly，also，and then，besides，in addition，further，furthermore，next，besides， moreover，what's more，last，last but not the least，finally
表举例for example，for instance
表解释in fact，as a matter of fact， frankly speaking，in this case，that is， namely，in other words
表总结in a word，in brief，in conclusion，to conclude，in short，in other words，it is true，thus，as has been said，in simpler terms，on the whole， therefore
表强调of course，indeed，above all，and equally important，most important，certainly
表比较in comparison，likewise， similarly，equally，however，in the same way
表转折but，in contrast，nevertheless，on the contrary，on the other hand，otherwise，though，yet，despite the fact that，even so，even though，for all that， however，in spite of，instead
表时间after a while，afterward， and then，as long as，at last，at that time， finally，in the past，now，at present，lately，meanwhile，presently，shortly，so far， soon，until，since，until now，when，before，after
