1) 先后次序关系：at this time; first; second; at last; next；previously; simultaneously; eventually；last but not least；to begin with；to start with；to end with；finally；seeing.；since then；first of all；afterwards; following this; preceding this. 2) 因果关系：because；because of this；being that；another important factorreason of. ； since； as； for； in that.； owing to； due to； for the reason that.； in view of； the reason seems to be obvious; there are about. ；for this reason; as a result of this；
