Doctor Brown says that what forceful arguments against cigarette harm there are, many people insist on smoking.
A. though
B. however
C. no matter
D. even if
网友回答
A. though
B. however
(答案→)C. no matter
D. even if
解析：B不能引导一个句子；C常与wh-句子连用；从句意上看此处只能是“无论”，所以C正确。