but, however, still, yet, after all, for all that, in spite of, on the contrary, on the other hand等，如：
③ jim is intelligent but lazy.
④ singapore is not a big country.on the contrary, it is very small.
ⅲ表示“困果关系”：
therefore, so, hence, thus, accordingly, consequently, as a result 等，如：
⑤ some people are over-ambitious. as a result, they are usually unhappy.
⑥ tom did not work hard; hence, he failed.
ⅳ表示“比较关系”：
likewise, similarly, in a like manner 等，如：
⑦ you cannot writes without a pen. likewise, you cannot cook without rice.
⑧ no one is allowed to speak mandarin in an english class. similarly, no one is allowed to speak english in a mandarin class.
ⅴ表示“举例示范”：
for example, in other words, for instance, that is 等，如：
⑨ there are some common errors in his composition. for instance,