1.表示时间：
now , then , afterwards , five minutes later , soon , before long , after that , meanwhile , to this day , just now , just then
2. 表示顺序：
first/firstly , first of all , second / secondly . next , third / thirdly , at first , at last , in the end , finally , next
3.表示递进关系：
besides, also , what’s more , in addition , even , once more , more over
4. 表示因果关系：
because , so , therefore , as a result , thanks to , because of , due to
5. 表示转折关系：
but , yet , however , while , on the contrary
6. 表示条件关系：
if , unless , as long as , so long as , on condition that
7. 表示结果：
thus , therefore , as a result , luckily , unfortunately
8. 表示强调关系：
above all , indeed , surely , certainly , of course , after all , at least , at most
generally speaking , I think , in other words , in a word , in short
10. 表示解释和说明：
that’s to say , for example , actually , and so on , such as , believe it or not , to tell the truth , according to , for this reason , in fact , in other words
11. 表示比较：
just like , just as , in the same way , more or less , sooner or later , on the hand , instead
12. 表示总结：
in conclusion , in a word , in generally , generally speaking , in short , as you know , in the end
