假设某数据库中,“宿舍表”中有“宿舍编号”字段为主键,则学生表中的“宿舍编号”字段称为____。
A. 主键
B. 外键
C. 外连接
D. 内连接
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概念模型既可以向关系模型转换,也可以像层次模型或网状模型转换。
A. 对
B. 错
How much is the monthly income of Michael's monthly budget?
A. 1,595 dollar
B. 605 dollar
C. 2,200 dollar
D. 2,500 dollar
Michael spends more than he gets each month.
A. 对
B. 错
The money from Michael's parents is enough to pay for his rent and groceries.
A. 对
B. 错