秦朝秘书官吏的来源有（）。
A.从开国功臣中选用
B.辟除
C.从六国旧部中招用
D.运用试吏法简选
E.学校培养、输送
参考答案：A, C, D
_____ he didn't know the custom in that country; otherwise, he wouldn't have made such a mistake. [ ]
A. Approximately
B. Accidentally
C. Obviously
D. Occasionally
在关系模型中，把数据看成一个二维表，每一个二维表称为一个 【5】 。
