---I have passed the popular election of the Olympics Maths Competition.
--- .You are always excellent in maths.
A. No wonder
B. Good luck
C. Congratulations
D. Good news
网友回答
A. No wonder
B. Good luck
(答案→)C. Congratulations
D. Good news
解析：考察固定习语，No wonder意思“难怪”， Good luck意思“好运”，当别人要参加或做什么事情时，你可以说Good luck，Congratulations意思“祝贺”，通过上句说他通过数学奥林匹克竞赛的竞选，后面答语肯定先祝贺别人，所以选C