关系模式R(U，F)，其中U={A，B，C，D，E}，F={AC→E，E→D，A→B，B→D}。关系模式R的候选键是(45)，(46)是无损连接并保持函数依赖的分解。
(56)
查看答案
A．She hasn't spoken to her friend in a long time.B．She intends to visit her friend in T
A. She hasn't spoken to her friend in a long time.
B. She intends to visit her friend in Texas.
C. She sometimes travels abroad for her job.
D. Her friend has never been to Texas before.
A．She's glad the man waited for her.B．She'd like to reschedule the meeting.C．She wasn'
A. She's glad the man waited for her.
B. She'd like to reschedule the meeting.
C. She wasn't very late for the meeting.
D. She's sorry that she missed the meeting.
A．程序、数据和标示符B．程序、数据和PCBC．程序、标示符和PCBD．数据、标示符和PCB
A. 程序、数据和标示符
B. 程序、数据和PCB
C. 程序、标示符和PCB
D. 数据、标示符和PCB
证券交易所对上市公司的股票进行特别处理不是对上市公司的处罚。()
A. 正确
B. 错误
微信支付 
支付宝支付