There are the following descriptions: ①The reciprocal of the integer a is (1/(a)); ②Because 4.8/0.8=6, so 4.8 is divisible by 0.8; ③There are 102 students in the first and second classes of the sixth grade. 102%; ④A project is completed by team A alone in 12 days, and team B in 9 days. The ratio of the work efficiency of teams A and B is 12:9. The number of errors
有下列叙述：①整数a的倒数是(1/(a))；②因为4.8/0.8=6，所以4.8能被0.8整除；③六年级一、二班共102人，全部到齐，出勤率102%；④一项工程由甲队单独做12天完成，乙队做9天完成，则甲、乙两队工作效率的比是12：9．其中错误的个数多少
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