Every day Express newspaper organizes expansion training. On the last day, all employees participating in the expansion are assessed. If the assessment results reach 3 or more, it is recorded as excellent. Before the assessment, several people discussed the results. Chen Dong said: "Xiao Jun, Xiao Xia's physical fitness is good, at least one of them is excellent. " Niu Li said: "The training time is too short, everyone practice is not enough, no one can be excellent this time. " Ma Fang said "how Is it possible? Someone has participated in training before and they will definitely be excellent. ". Assuming that the guess of only one of these three people has been verified, which of the following conclusions must be derived? ? ['Niu Li is right, no member of the newspapers participating in the expansion is outstanding.', "Can't determine right or wrong, but all trainees get excellent.", 'Ma Fang is right, some people are excellent, but some people are not.', 'Chen Dong was wrong, Xiaoxia did not get excellent.']