1.表示列举和举例
    
    first of all，for one thing，for another，to begin with，first，second，next，in the first (second) place，furthermore，moreover，beyond that，also，besides，in addition，what is more，such as，finally; for example，for instance等。
    
    2.表示原因
    
    since，because (of)，as，for，owing to，result from，due to，on account of，on the ground of，as a result of等。
    
    3.表示时间顺序
    
    at the same time，as soon as，so far，since，then，until，when，meanwhile，shortly，later，lately，after a while，at that time，before，earlier，presently，in the meantime，formerly等。
    
    4.表示空间顺序
    
    close to，close at hand（近在身旁），next to，down，far，beyond，against（对着），on the opposite side（相对的），opposite to，above，across，across from，around，at the bottom，before，behind，below，beneath，between，in the middle of，in the distance，in the center of，farther，on the left/right等。
    
    5.表示重复
    
    in other words，again，as has been pointed out，to repeat，as I have said above，once again，after all，indeed，in fact，truly，of course，chiefly，especially，certainly，actually，particularly，to be sure，above all，surely，most important of all，even worse，no doubt，needless to say等。
    
    6.表示结果
    
    so，then，therefore，thus，hence，consequently，as a result，accordingly，for this reason，as a consequence，on that account，it follows that等。
    
    7.表示总结
    
    to sum up，in summary，to summarize，in short，in brief，to be brief，in other words，on the whole，in conclusion，to conclude等。
    
    8.表示对比和对照
    
    （1）对照：but，however，yet，or，nevertheless，still，nonetheless，conversely，nor，rather，whereas，thought，on the one hand，on the other hand，on the contrary，by contrast with/to，in contrast (with/to)，even though，instead，unlike，different from，instead (of)，the opposite (of)，unlike，although，while，but等。
    
    （2）对比：similarly，likewise，like，as，at the same time，in fact，too，in the same way，in a like manner，both，each，also，compared with等。