Up to now, no one has e up with a（n） explanation of why dinosaurs died out, and it remains a mystery．
A. astonishing
B. amusing
C. convincing
D. puzzling
网友回答
A. astonishing
B. amusing
(答案→)C. convincing
D. puzzling
解析：A．astonishing 令人惊讶的，B．amusing令人发笑的，C．convincing令人信服的，D．puzzling令人困惑的，句意：直到现在，没有人给出一个令人信服的解释为什么恐龙会灭绝，这仍然是和迷。所以选C。