1、强调关系
in fact; especially;particularly;moreover;naturally; what is more important; in reality; certainly; of course; indeed; in particular;not to mention...;believe it or not;undeniably; other thing being equal;it is certain/sure that...;to be strict; to be true;by definition; definitely; undoubtedly; without a doubt; in truth, in any event(不论怎样); without reservation(毫无保留地); obviously, not only.. but(also...), both... and...
2、条件关系
if;unless; lest;provided that;if it is the case;in this sense;once...;if possible;if necessary;if so;if not all; if anything.
3、(补充)递进关系
furthermore;moreover;further;In this way ;still; not only...but also...; not...but...; in addition (to);additionally, much more interesting, more specifically, next, besides; as far as... is concerned; moreover;in other words;along this line of consideration;on the one hand...，on the other hand...; even; as a poplar saying goes...;in order to do it...; meanwhile; at the same time; accordingly; In the first place...，in the second place...;equally important; of even greater appeal.