1. 表示因果类关键词:
as a result, result in, result from, lead to, because of, due to, contribute to, owning to, hence, since, accordingly, consequently, therefore, in that, etc.
2. 表示转折类关键词:
despite, in spite of, but, although, though, while, yet, otherwise, on the other hand, however, nevertheless, nonetheless, etc.
3. 表示比较类关键词:
more, than, less, the least, the most, prefer, equally, likewise, similarly, in comparison, as…as, etc.