表对比whereas, while, as opposed to, by contrast, by comparison, on the contrary, oppositely, but, yet
表示时间:in general, every, some, sometimes, after, on the whole, usually, most, at other times, in most cases, frequently, main, finally, as a rule, rarely, before, meanwhile
表示转折:although, instead, rather than, but, nevertheless, though, however, on the other hand, otherwise
表示时间顺序：now，then，before，after，afterwards，earlier，later，immediately，soon，next，in a few days，gradually，suddenly，finally
表示空间顺序：near(to)，far(from)，in front of，behind，beside，beyond，above，below，to the right (left)，around，outside
表示对照：but，still，yet，however，on the other hand，on the contrary，in spite of，even though等。
表示结果和原因：because，since，so，as a result，therefore，hence，thus，otherwise等。
表示目的：for this reason，for this purpose，so that等。
表示强调：in fact，indeed，surely，necessarily，certainly，without any doubt，truly，to repeat，above all，most important等。
表示解释说明：for example，in fact，in this case，for actually
表示总结：finally，at last，in conclusion，as I have shown，in other words，in brief，in short，in general，on the whole，as has been stated
