递进：further more, moreover, besides, in addition, then，etc.
转折：however, but, nevertheless, after all，etc.
总结：finally, at last, in brief, to conclude
强调：really, indeed, certainly, surely, above all，etc.
对比：in the same way, just as, on the other hand, etc.
举例说明：for example; Take . . . for example.
列举例证或观点：First; Second; Third; Last;One is . . .; another ; still another
因果：because (of); result from; therefore; accordingly; result in
分类：. . . can be classified into . . .; . . . fall into several classes/categories
表达意见：I think; in my opinion; as far as I’m concerned
开头句常用：It’s generally believed that . . .
Various views exist as to . . .
There is much discussion about . . .
结尾句常用：To conclude; to sum up; all in all