4.因果(Cause and effect)

　　because, because of, for, since, due to, owing to, thanks to, as a result(of), accordingly, hence, so, thus, as, therefore ,in that, consequently, as a consequence ,so that, to this end.

　　5.强调(Emphasis)

　　certainly, above all, indeed, of course, surely, actually, as a matter of fact, chiefly, especially, primarily, in particular, undoubtedly, absolutely, most important

　　6.让步(Concession)

　　although, though, after all, in spite of, nevertheless, still, provided, while it is true....if,

　　only if, despite, even so ,even though, rather, while, regardless .

　　7.例证(Exemplification)

　　for example, for instance, that is, namely, such as, in other words, in this case, by way of , illustration,. finally, still, as an example, specifically, in particular ,next, another .

　　8.总结(Conclusion)

　　to sum up, to conclude, in a word, in short, in brief, all in all, in all, to put it in a nutshell, in summary