They think they’re right; , they are pletely wrong.
A. but
B. although
C. though
D. however
网友回答
A. but
B. although
C. though
(答案→)D. however
解析：连词辨析.句意,他们认为他们是对的;可是,他们是完全的错了. but是并列名词，连接两个并列分句however不能直接连接两个分句，必须另起新句，并用逗号隔开。but 口语常用词，语气较强，泛指与前述情况相反。 however 表转折关系，语气稍弱于but，连接性也弱一些，因而常作插入语。选D.