--- I was lucky to win a gold medal in the 800-meter-race.
--- You through tough training.
A. must go
B. should go
C. must have gone
D. should have gone
网友回答
A. must go
B. should go
(答案→)C. must have gone
D. should have gone
解析：句意：——我幸运的在800米赛跑中得了金牌。——你一定经过了艰苦的训练。根据句意，与过去有关，排除ＡＢ。Must 一定，必须，must have done（过去)一定做了某事，should应该，should have done本应该做某事而实际没做，故选Ｃ