高二某班小A是师生眼里的差生,却在一次学校卫生大检查时,其他同学因有活动提前离开学校后,她独自一人用近一个小时,把教室打扫得干干净净。高二某班小B担任班长,一向优秀,曾被评为市、区级优秀干部,却在一次大考中作弊。以上两例几乎同时发生,乍看令人费解,但是在现实中又不乏其例,具有一定普通性。这不由地引人思考为什么在关键时候学生的表现与平时给人的印象大相径庭,即优生不优、差生不差? A class sophomore sophomore is poor students in the eyes of teachers and students, but in a large school health examination, other students leave early due to activities of the school, she alone with almost an hour, clean the classroom clean. A class sophomore sophomore squad leader, has always been excellent, has been rated as city, district cadres, but cheated in a big exam. The above two cases occurred almost simultaneously, at first glance puzzling, but in reality there is no shortage of cases, with some generality. This can not help but think about why the performance of students in the critical moment and usually gives the impression of very different, that is, eugenics not good, poor students are not bad?