奴隶社会______的出现，标志着教育与生产劳动的第一次分离。
参考答案：学校
He told me he had finished the work ________. [ ]
A. two days ago
B. the day before yesterday
C. the next day
D. the day before
下面哪种网元不会产生CDR话单（）
A.MME
B.PGW
C.SGW
D.GGSN
