2012CET六級寫作詞匯輔導(dǎo)：表示轉(zhuǎn)折

but 但是
    But modern research has found that this is not so.
    但是現(xiàn)代研究表明事實并非如此。
    however 然而（可位于句前、句中和句首，與其他成分隔開）
    His first response was to say no. Later, however, he changed his mind. 他最初的反應(yīng)是不同意，可是后來他改變了主意。
    though 然而，但是
    Though he is rich, his life is not happy. 他雖然很有錢,但生活并不幸福。
    while 然而
    As far as I am concerned, some people are lucky while others seem marked by bad fortune. 據(jù)我所知，一些人很幸運，然而一些人卻很不幸。